Diseases of the Circulatory System: (ICD-9-CM Chapter 7, Codes 390-459, and ICD-10-CM Chapter 9, Codes I00-I99)



Diseases of the Circulatory System


(ICD-9-CM Chapter 7, Codes 390-459, and ICD-10-CM Chapter 9, Codes I00-I99)



Learning Objectives



1. Apply and assign the correct ICD-9-CM and ICD-10-CM codes in accordance with Official Guidelines for Coding and Reporting


2. Identify major differences between ICD-9-CM and ICD-10-CM related to diseases of the circulatory system


3. Identify pertinent anatomy and physiology of the circulatory system


4. Identify diseases of the circulatory system


5. Assign the correct V/Z codes and procedure codes related to the circulatory system


6. Identify common treatments, medications, laboratory values, and diagnostic tests


7. Explain the importance of documentation in relation to MS-DRGs for reimbursement



Abbreviations/Acronyms














































































ICD-9-CM Official Guidelines for Coding and Reporting


Please refer to the companion Evolve website for the most current guidelines.




7. Chapter 7: Diseases of Circulatory System (390-459)



a. Hypertension


    Hypertension Table


    The Hypertension Table (Figure 15-1), found under the main term, “Hypertension”, in the Alphabetic Index, contains a complete listing of all conditions due to or associated with hypertension and classifies them according to malignant, benign, and unspecified.


image
Figure 15-1 Hypertension table in Alphabetic Index.

    



1) Hypertension, Essential, or NOS


    Assign hypertension (arterial) (essential) (primary) (systemic) (NOS) to category code 401 with the appropriate fourth digit to indicate malignant (.0), benign (.1), or unspecified (.9). Do not use either .0 malignant or .1 benign unless medical record documentation supports such a designation.



Example


Hypertension, 401.9 (I10).




Example


Malignant hypertension, 401.0 (I10).



Example


Benign hypertension, 401.1 (I10).


2) Hypertension with Heart Disease


    Heart conditions (425.8, 429.0-429.3, 429.8, 429.9) are assigned to a code from category 402 when a causal relationship is stated (due to hypertension) or implied (hypertensive). Use an additional code from category 428 to identify the type of heart failure in those patients with heart failure. More than one code from category 428 may be assigned if the patient has systolic or diastolic failure and congestive heart failure.


    The same heart conditions (425.8, 429.0-429.3, 429.8, 429.9) with hypertension, but without a stated causal relationship, are coded separately. Sequence according to the circumstances of the admission/encounter.



Example


Congestive heart failure due to hypertensive heart disease, 402.91, 428.0 (I11.0, I50.9).




Example


Congestive heart failure in a patient with hypertension, 428.0, 401.9 (I50.9, I10).


3) Hypertensive Chronic Kidney Disease


    Assign codes from category 403, Hypertensive chronic kidney disease, when conditions classified to category 585 or code 587 are present with hypertension. Unlike hypertension with heart disease, ICD-9-CM presumes a cause-and-effect relationship and classifies chronic kidney disease (CKD) with hypertension as hypertensive chronic kidney disease.


    Fifth digits for category 403 should be assigned as follows:


    



The appropriate code from category 585, Chronic kidney disease, should be used as a secondary code with a code from category 403 to identify the stage of chronic kidney disease.


See Section I.C.10.a for information on the coding of chronic kidney disease.



Example


The patient was admitted with acute renal failure. The patient was given secondary diagnoses of benign hypertension and chronic kidney disease, stage III, 584.9, 403.10, 585.3 (N17.9, I12.9, N18.3).


4) Hypertensive Heart and Chronic Kidney Disease


    Assign codes from combination category 404, Hypertensive heart and chronic kidney disease, when both hypertensive kidney disease and hypertensive heart disease are stated in the diagnosis. Assume a relationship between the hypertension and the chronic kidney disease, whether or not the condition is so designated. Assign an additional code from category 428, to identify the type of heart failure. More than one code from category 428 may be assigned if the patient has systolic or diastolic failure and congestive heart failure.


    Fifth digits for category 404 should be assigned as follows:


    



The appropriate code from category 585, Chronic kidney disease, should be used as a secondary code with a code from category 404 to identify the stage of kidney disease.


See Section I.C.10.a for information on the coding of chronic kidney disease.


5) Hypertensive Cerebrovascular Disease


    First assign codes from 430-438, Cerebrovascular disease, then the appropriate hypertension code from categories 401-405.



Example


Cerebrovascular accident in a patient with malignant hypertension, 434.91, 401.0 (I63.9, I10).



6) Hypertensive Retinopathy


    Two codes are necessary to identify the condition. First assign the code from subcategory 362.11, Hypertensive retinopathy, then the appropriate code from categories 401-405 to indicate the type of hypertension.



Example


The patient is being treated for bilateral retinopathy due to labile hypertension, 362.11, 401.9 (H35.033, I10).



7) Hypertension, Secondary


    Two codes are required: one to identify the underlying etiology and one from category 405 to identify the hypertension. Sequencing of codes is determined by the reason for admission/encounter.



Example


Hypertension due to periarteritis nodosa, 446.0, 405.99 (M30.0, I15.8).



8) Hypertension, Transient


    Assign code 796.2, Elevated blood pressure reading without diagnosis of hypertension, unless patient has an established diagnosis of hypertension.


    Assign code 642.3x for transient hypertension of pregnancy.



Example


The patient has an elevated blood pressure caused by the stress of being in an MVA, 796.2 (R03.0).


9) Hypertension, Controlled


    Assign appropriate code from categories 401-405. This diagnostic statement usually refers to an existing state of hypertension under control by therapy.



Example


The patient’s benign hypertension has been well controlled since the patient lost 20 pounds and started a regular exercise program, 401.1 (I10).



10) Hypertension, Uncontrolled


    Uncontrolled hypertension may refer to untreated hypertension or hypertension not responding to current therapeutic regimen. In either case, assign the appropriate code from categories 401-405 to designate the stage and type of hypertension. Code to the type of hypertension.



Example


The patient’s hypertension has been uncontrolled for the past 2 months in spite of changes in medication, 401.9 (I10).



11) Elevated Blood Pressure


    For a statement of elevated blood pressure without further specificity, assign code 796.2, Elevated blood pressure reading without diagnosis of hypertension, rather than a code from category 401.



Example


The patient has high blood pressure; will recheck at next clinic visit. No medications were given, 796.2 (R03.0).



b. Cerebral infarction/stroke/cerebrovascular accident (CVA)


    The terms stroke and CVA are often used interchangeably to refer to a cerebral infarction. The terms stroke, CVA, and cerebral infarction NOS are all indexed to the default code 434.91, Cerebral artery occlusion, unspecified, with infarction.


    Additional code(s) should be assigned for any neurologic deficits associated with the acute CVA, regardless of whether or not the neurologic deficit resolves prior to discharge.


    See Section I.C.18.d.3 for information on coding status post administration of tPA in a different facility within the last 24 hours.


c. Postoperative cerebrovascular accident


    A cerebrovascular hemorrhage or infarction that occurs as a result of medical intervention is coded to 997.02, Iatrogenic cerebrovascular infarction or hemorrhage. Medical record documentation should clearly specify the cause-and-effect relationship between the medical intervention and the cerebrovascular accident in order to assign this code. A secondary code from the code range 430-432 or from a code from subcategories 433 or 434 with a fifth digit of “1” should also be used to identify the type of hemorrhage or infarct.


    This guideline conforms to the use additional code note instruction at category 997. Code 436, Acute, but ill-defined, cerebrovascular disease, should not be used as a secondary code with code 997.02.



Example


The patient had a postoperative cerebrovascular accident, which was embolic in nature. The patient had initially been admitted for treatment of coronary artery arteriosclerosis with CABG (left internal mammary artery and two open saphenous vein grafts from the left saphenous vein were used). Cardiopulmonary bypass was used during the surgery, 414.01, 997.02, 434.11, E878.2, E849.7, 36.12, 36.15, 39.61 (I25.10, I97.820, I63.40, 021109W, 02100A9, 5A1221Z, 06BQ0ZZ).



d. Late Effects of Cerebrovascular Disease



1) Category 438, Late Effects of Cerebrovascular Disease


    Category 438 is used to indicate conditions classifiable to categories 430-437 as the causes of late effects (neurologic deficits), themselves classified elsewhere. These “late effects” include neurologic deficits that persist after initial onset of conditions classifiable to 430-437. The neurologic deficits caused by cerebrovascular disease may be present from the onset or may arise at any time after the onset of the condition classifiable to 430-437.


    Codes in category 438 are only for use for late effects of cerebrovascular disease, not for neurologic deficits associated with an acute CVA.



Example


Aphasia due to cerebrovascular accident 3 months ago, 438.11 (I69.320).




Example


The patient was admitted with left-sided hemiparesis due to a cerebrovascular accident. The patient has a history of previous CVA with residual facial droop, 434.91, 342.90, 438.83 (I63.9, G81.94, I69.392).


2) Codes from category 438 with codes from 430-437


    Codes from category 438 may be assigned on a healthcare record with codes from 430-437, if the patient has a current cerebrovascular accident (CVA) and deficits from an old CVA.


3) Code V12.54


    Assign code V12.54, Transient ischemic attack (TIA), and cerebral infarction without residual deficits (and not a code from category 438) as an additional code for history of cerebrovascular disease when no neurologic deficits are present.



Example


The patient had a CVA in 2002 with no residuals, V12.54 (Z86.73).



e. Acute myocardial infarction (AMI)



1) ST elevation myocardial infarction (STEMI) and non ST elevation myocardial infarction (NSTEMI)


    The ICD-9-CM codes for acute myocardial infarction (AMI) identify the site, such as anterolateral wall or true posterior wall. Subcategories 410.0-410.6 and 410.8 are used for ST elevation myocardial infarction (STEMI). Subcategory 410.7, Subendocardial infarction, is used for non ST elevation myocardial infarction (NSTEMI) and nontransmural MIs (Figure 15-2).


image
Figure 15-2 Tabular entry for 410, Acute myocardial infarction.

2) Acute myocardial infarction, unspecified


    Subcategory 410.9 is the default for the unspecified term acute myocardial infarction. If only STEMI or transmural MI without the site is documented, query the provider as to the site, or assign a code from subcategory 410.9.


3) AMI documented as nontransmural or subendocardial but site provided


    If an AMI is documented as nontransmural or subendocardial, but the site is provided, it is still coded as a subendocardial AMI. If NSTEMI evolves to STEMI, assign the STEMI code. If STEMI converts to NSTEMI due to thrombolytic therapy, it is still coded as STEMI.



Example


The patient was admitted with NSTEMI, 410.71 (I21.4).




Example


The patient was admitted with anterolateral wall STEMI, 410.01 (I21.09).


    Apply the General Coding Guidelines as found in Chapter 5 and the Procedural Guidelines as found in Chapter 6.



ICD-10-CM Official Guidelines for Coding and Reporting


Please refer to the companion Evolve website for the most current guidelines.




9. Chapter 9: Diseases of Circulatory System (I00-I99)



a. Hypertension



1) Hypertension with Heart Disease


    Heart conditions classified to I50.- or I51.4-I51.9, are assigned to, a code from category I11, Hypertensive heart disease, when a causal relationship is stated (due to hypertension) or implied (hypertensive). Use an additional code from category I50, Heart failure, to identify the type of heart failure in those patients with heart failure.


    The same heart conditions (I50.-, I51.4-I51.9) with hypertension, but without a stated causal relationship, are coded separately. Sequence according to the circumstances of the admission/encounter.


2) Hypertensive Chronic Kidney Disease


    Assign codes from category I12, Hypertensive chronic kidney disease, when both hypertension and a condition classifiable to category N18, Chronic kidney disease (CKD), are present. Unlike hypertension with heart disease, ICD-10-CM presumes a cause-and-effect relationship and classifies chronic kidney disease with hypertension as hypertensive chronic kidney disease.


    The appropriate code from category N18 should be used as a secondary code with a code from category I12 to identify the stage of chronic kidney disease.


    See Section I.C.14. Chronic kidney disease.


    If a patient has hypertensive chronic kidney disease and acute renal failure, an additional code for the acute renal failure is required.


3) Hypertensive Heart and Chronic Kidney Disease


    Assign codes from combination category I13, Hypertensive heart and chronic kidney disease, when both hypertensive kidney disease and hypertensive heart disease are stated in the diagnosis. Assume a relationship between the hypertension and the chronic kidney disease, whether or not the condition is so designated. If heart failure is present, assign an additional code from category I50 to identify the type of heart failure.


    The appropriate code from category N18, Chronic kidney disease, should be used as a secondary code with a code from category I13 to identify the stage of chronic kidney disease.


    See Section I.C.14. Chronic kidney disease.


    The codes in category I13, Hypertensive heart and chronic kidney disease, are combination codes that include hypertension, heart disease and chronic kidney disease. The Includes note at I13 specifies that the conditions included at I11 and I12 are included together in I13. If a patient has hypertension, heart disease and chronic kidney disease then a code from I13 should be used, not individual codes for hypertension, heart disease and chronic kidney disease, or codes from I11 or I12.


    For patients with both acute renal failure and chronic kidney disease an additional code for acute renal failure is required.


4) Hypertensive Cerebrovascular Disease


    For hypertensive cerebrovascular disease, first assign the appropriate code from categories I60-I69, followed by the appropriate hypertension code.


5) Hypertensive Retinopathy


    Subcategory H35.0, Background retinopathy and retinal vascular changes should be used with a code from category I10 – I15, Hypertensive disease to include the systemic hypertension. The sequencing is based on the reason for the encounter.


6) Hypertension, Secondary


    Secondary hypertension is due to an underlying condition. Two codes are required: one to identify the underlying etiology and one from category I15 to identify the hypertension. Sequencing of codes is determined by the reason for admission/encounter.


7) Hypertension, Transient


    Assign code R03.0, Elevated blood pressure reading without diagnosis of hypertension, unless patient has an established diagnosis of hypertension. Assign code O13.-, Gestational [pregnancy-induced] hypertension without significant proteinuria, or O14.-, Pre-eclampsia, for transient hypertension of pregnancy.


8) Hypertension, Controlled


    This diagnostic statement usually refers to an existing state of hypertension under control by therapy. Assign the appropriate code from categories I10-I15, Hypertensive diseases.


9) Hypertension, Uncontrolled


    Uncontrolled hypertension may refer to untreated hypertension or hypertension not responding to current therapeutic regimen. In either case, assign the appropriate code from categories I10-I15, Hypertensive diseases.


b. Atherosclerotic Coronary Artery Disease and Angina


    ICD-10-CM has combination codes for atherosclerotic heart disease with angina pectoris. The subcategories for these codes are I25.11, Atherosclerotic heart disease of native coronary artery with angina pectoris and I25.7, Atherosclerosis of coronary artery bypass graft(s) and coronary artery of transplanted heart with angina pectoris.


    When using one of these combination codes it is not necessary to use an additional code for angina pectoris. A causal relationship can be assumed in a patient with both atherosclerosis and angina pectoris, unless the documentation indicates the angina is due to something other than the atherosclerosis.


    If a patient with coronary artery disease is admitted due to an acute myocardial infarction (AMI), the AMI should be sequenced before the coronary artery disease.


    See Section I.C.9. Acute myocardial infarction (AMI)


c. Intraoperative and Postprocedural Cerebrovascular Accident


    Medical record documentation should clearly specify the cause- and-effect relationship between the medical intervention and the cerebrovascular accident in order to assign a code for intraoperative or postprocedural cerebrovascular accident.


    Proper code assignment depends on whether it was an infarction or hemorrhage and whether it occurred intraoperatively or postoperatively. If it was a cerebral hemorrhage, code assignment depends on the type of procedure performed.


d. Sequelae of Cerebrovascular Disease



1) Category I69, Sequelae of Cerebrovascular disease


Category I69 is used to indicate conditions classifiable to categories I60-I67 as the causes of sequela (neurologic deficits), themselves classified elsewhere. These “late effects” include neurologic deficits that persist after initial onset of conditions classifiable to categories I60-I67. The neurologic deficits caused by cerebrovascular disease may be present from the onset or may arise at any time after the onset of the condition classifiable to categories I60-I67.


2) Codes from category I69 with codes from I60-I67


Codes from category I69 may be assigned on a health care record with codes from I60-I67, if the patient has a current cerebrovascular disease and deficits from an old cerebrovascular disease.


3) Code Z86.73


Assign code Z86.73, Personal history of transient ischemic attack (TIA), and cerebral infarction without residual deficits (and not a code from category I69) as an additional code for history of cerebrovascular disease when no neurologic deficits are present.


e. Acute myocardial infarction (AMI)



1) ST elevation myocardial infarction (STEMI) and non ST elevation myocardial infarction (NSTEMI)


    The ICD-10-CM codes for acute myocardial infarction (AMI) identify the site, such as anterolateral wall or true posterior wall. Subcategories I21.0-I21.2 and code I21.3 are used for ST elevation myocardial infarction (STEMI). Code I21.4, Non-ST elevation (NSTEMI) myocardial infarction, is used for non ST elevation myocardial infarction (NSTEMI) and nontransmural MIs.


    If NSTEMI evolves to STEMI, assign the STEMI code. If STEMI converts to NSTEMI due to thrombolytic therapy, it is still coded as STEMI.


    For encounters occurring while the myocardial infarction is equal to or less than four weeks old, including transfers to another acute setting or a postacute setting, and the patient requires continued care for the myocardial infarction, codes from category I21 may continue to be reported. For encounters after the 4-week time frame, if the patient is still receiving care related to the myocardial infarction, the appropriate aftercare code should be assigned, rather than a code from category I21. For old or healed myocardial infarction not requiring further care, code I25.2, Old myocardial infarction, may be assigned.


2) Acute myocardial infarction, unspecified


    Code I21.3, ST elevation (STEMI) myocardial infarction of unspecified site, is the default for the unspecified term acute myocardial infarction. If only STEMI or transmural MI without the site is documented, query the provider as to the site, or assign code I21.3.


3) AMI documented as nontransmural or subendocardial but site provided


    If an AMI is documented as nontransmural or subendocardial, but the site is provided, it is still coded as a subendocardial AMI.


    See Section I.C.21.3 for information on coding status post administration of tPA in a different facility within the last 24 hours.


4) Subsequent acute myocardial infarction


    A code from category I22, Subsequent ST elevation (STEMI) and non ST elevation (NSTEMI) myocardial infarction, is to be used when a patient who has suffered an AMI has a new AMI within the 4 week time frame of the initial AMI. A code from category I22 must be used in conjunction with a code from category I21. The sequencing of the I22 and I21 codes depends on the circumstances of the encounter.


    Apply the General Coding Guidelines as found in Chapter 5 and the Procedural Guidelines as found in Chapter 7.




Major Differences between ICD-9-CM and ICD-10-CM




• The code for gangrene has been moved from the symptom chapter in ICD-9-CM to Diseases of the Circulatory System in ICD-10-CM.


• The section Late Effects of Cerebrovascular Disease has been expanded to include more specificity and laterality.


• The time limit for assigning the acute MI code is 28 days in ICD-10-CM, whereas in ICD-9-CM, it was 8 weeks.


• A new category has been added for coding a subsequent acute MI, which is an MI that occurs within 28 days of a previous acute MI.


• A new category for complications within 28 days of acute MI has been added.


• Transient ischemic attack has been reclassified to the nervous system chapter.


• Stages of chronic kidney disease are no longer found as fifth digits but are assigned a separate code.


• Subsequent acute MI is new to I10. This is a new MI that occurs in a patient who suffered a previous new MI within the last 4 weeks.



Anatomy and Physiology


The circulatory system is composed of the heart and blood vessels (Figure 15-3). Its function is to supply tissue in the body with oxygen and nutrients. This function is accomplished when the arteries carry blood (oxygen) to the cells. The largest artery, the aorta, branches off the heart and divides into many smaller arteries. The veins carry deoxygenated blood to the lungs to acquire oxygen and then to the heart, whose job it is to pump oxygenated blood back to the arteries.


image
Figure 15-3 The heart and great vessels, posterior view.


The Heart


The function of the heart is to pump oxygen-rich blood to the cells of the body. The heart itself receives oxygenated blood from the coronary arteries; the two major coronary arteries branch off the aorta.


The heart is enclosed laterally by the lungs, posteriorly by the backbone, and anteriorly by the sternum. The wall of the heart is composed of three layers: epicardium, myocardium, and endocardium (Figure 15-4). The epicardium is the outer protective layer, the myocardium is the middle layer and is composed of cardiac muscle, and the endocardium is the inner layer that lines all of the heart chambers and covers the heart valves.


image
Figure 15-4 Layers of the heart wall.

The heart consists of four chambers: right atrium, left atrium, right ventricle, and left ventricle. The atrium and the ventricle on the right side are separated from the left by a septum. The top two chambers, the atria, receive blood via the veins from the body or the lungs. The right ventricle pumps blood to the lungs to pick up oxygen, and the left ventricle pumps blood to the rest of the body. Within the heart are four valves (Figure 15-5), and their job is to direct blood flow. The tricuspid valve is located between the right atrium and the right ventricle. The valve between the left atrium and the left ventricle is the mitral or bicuspid valve. The aortic valve is located in the aorta at the point at which the left ventricle empties into the aorta. The pulmonary valve is located in the pulmonary artery at the point of exit from the right ventricle.


image
Figure 15-5 Cardiac valves.




Disease Conditions


Diseases of the Circulatory System (390-459), Chapter 7 in the ICD-9-CM code book, is divided into the following categories:



































CATEGORY SECTION TITLES
390-392 Acute Rheumatic Fever
393-398 Chronic Rheumatic Heart Disease
401-405 Hypertensive Disease
410-414 Ischemic Heart Disease
415-417 Diseases of Pulmonary Circulation
420-429 Other Forms of Heart Disease
430-438 Cerebrovascular Disease
440-449 Diseases of the Arteries, Arterioles, and Capillaries
451-459 Diseases of the Veins and Lymphatics and Other

Diseases of the Circulatory System (I00-I99), Chapter 9 in the ICD-10-CM code book, is divided into the following categories:






































CATEGORY SECTION TITLES
I00-I02 Acute Rheumatic Fever
I05-I09 Chronic Rheumatic Heart Disease
I10-I15 Hypertensive Diseases
I20-I25 Ischemic Heart Diseases
I26-I28 Pulmonary Heart Disease and Diseases of Pulmonary Circulation
I30-I52 Other Forms of Heart Disease
I60-I69 Cerebrovascular Diseases
I70-I79 Diseases of Arteries, Arterioles, and Capillaries
I80-I89 Diseases of Veins, Lymphatic Vessels, and Lymph Nodes, Not Elsewhere Classified
I95-I99 Other and Unspecified Disorders of the Circulatory System


Acute Rheumatic Fever and Chronic Rheumatic Heart Disease


Acute rheumatic fever is an inflammatory disease usually found in children that may affect the heart, joints, skin, or brain following an infection with streptococcal bacteria such as strep throat or scarlet fever.



Example


Patient was admitted with acute rheumatic fever with endocarditis, 391.1 (I01.1).



Example


Patient has rheumatic chorea without heart involvement, 392.9 (I02.9).


Chronic rheumatic heart disease is a chronic condition that is usually a late effect of attacks of acute rheumatic fever and most often involves the heart valves. When mitral and aortic valves are both involved, ICD-9-CM assumes a causal relationship to rheumatic heart disease.




Example


Aortic stenosis, 424.1 (I35.0).



Example


Aortic stenosis with mitral stenosis, 396.0 (I08.0).


Mitral stenosis, mitral valve disease unspecified, and mitral valve failure are presumed by ICD-9-CM to be rheumatic in origin.



Example


Stenosis, mitral, 394.0 (I05.0).


If one mitral valve condition is presumed rheumatic and more than one mitral valve condition exists, ICD-9-CM assumes that both conditions are rheumatic.



Unless otherwise specified, diseases of the tricuspid valve are presumed to be rheumatic in nature.



Hypertensive Disease


The codes for hypertension are located in a table (see Figure 15-1) found in the Alphabetic Index of diseases in ICD-9-CM. The three columns within this table identify the course of the disease: malignant, benign, or unspecified. There is no Hypertension Table in ICD-10-CM. The course of the disease in ICD-10-CM (benign, malignant, or unspecified) is not a requirement for assigning a code.



Example


Patient has chronic benign hypertension due to renal artery stenosis, 440.1, 405.11 (I70.1, I15.0).


Hypertension is classified by ICD-9-CM as primary (essential) or secondary. Primary hypertension, or high blood pressure (BP), is a condition that is defined as abnormally high blood pressure in the arterial system. The American Heart Association defines hypertension as pressures exceeding 140/90. A diagnosis of hypertension can be made only by a physician and should not be assigned on the basis of BP readings alone. Essential hypertension has no known origin, and its symptoms are insidious. ICD-9-CM uses fourth digits that describe the course of the disease. These fourth digits are as follows:



Secondary hypertension is a consequence of other diseases such as kidney diseases, brain tumor, or polycythemia, and coding requires these same fourth digits. When secondary hypertension is documented, the sequencing of the codes is determined by the reason for admission/encounter.



Example


Patient has hypertension due to Cushing’s disease, 255.0, 405.99 (E24.9, I15.2).



Benign, Malignant, and Uncontrolled Hypertension


Malignant hypertension is a very severe form of hypertension and may be a life-threatening condition. The coding of malignant hypertension must be documented by a physician. In cases of malignant hypertension, systolic pressure may be greater than 200, and diastolic may be greater than 120. Malignant hypertension is also known as accelerating or necrotizing hypertension. Patients are at greater risk for malignant hypertension if they experience renal failure.


Coding Clinic (1984:July-Aug:p12)1 describes malignant hypertension as “rapidly rising blood pressure, usually in excess of 140 mm Hg diastolic with findings of visual impairment and symptoms or signs of progressive cardiac failure.” The fact that hypertension is documented as uncontrolled or hypertensive emergency or hypertensive urgency does not make it malignant, and a separate code is not used to describe these conditions. Benign hypertension is rarely documented by physicians; therefore, coders often must assign the unspecified code. Hypertension that is not specifically documented as malignant or benign must be assigned to the unspecified fourth digit. Often, physicians document a history of hypertension when referring to ongoing hypertension that is under control. The current medication list should be reviewed to determine whether the hypertension is currently under treatment.



Example


Uncontrolled hypertension, 401.9 (I10).



Example


Hypertension, accelerated, 401.0 (I10).


Medications often used for treating hypertension include Accupril, Aldomet, captopril, Cardizem, diltiazem, Cozaar, losartan, Coreg, dyazide, Hytrin, Inderal, Lopressor, Norvasc, Procardia, Tenormin, atenolol, Vasotec, Toprol, Calan, verapamil, Zestril, and lisinopril.



Example


Patient has a past history of hypertension, currently taking verapamil, 401.9 (I10).


For a variety of reasons, patients may have elevated blood pressure readings. Per Coding Clinic (1990:3Q:p4),2 unless a patient has an established diagnosis of hypertension, the code 796.2 (R03.0) elevated blood pressure, should be assigned.



Hypertensive Heart, Renal, and Heart and Renal Disease


Per Coding Clinic (2003:1Q:p20-21),3 “ICD-9-CM assumes a cause-and-effect relationship and classifies chronic renal failure with hypertension as hypertensive renal disease.” This indicates to the coder that anytime hypertension and chronic renal failure (codes from category 585) (N18) occur in a patient, category 403 (I12) should be assigned. The only time the 403 (I12) category code would not be selected is when the physician documents, “CRF not due to hypertension.” On occasion, a patient will have chronic kidney disease (CKD) due to diabetes and also have hypertension; diabetic kidney disease and hypertensive kidney disease would both be assigned in these cases.


Hypertensive heart disease, in contrast to hypertensive renal disease, does not assume a cause-and-effect relationship. A causal relationship must be stated by the physician. For a code from this category to be assigned, the physician must document hypertensive heart disease or must say that heart disease is due to hypertension. This category includes heart failure as a fifth digit. It is important to note that if a patient has hypertensive congestive heart failure, at least two codes—402.x1 (I11.0) and 428.0 (I50.-)—are required; if known, the codes for systolic (428.20-428.23) (I50.2-), diastolic (428.30-428.33) (I50.3-), or a combination systolic and diastolic (428.40-428.43) (I50.4-) should also be assigned.



Example


Patient is admitted with both diastolic and systolic congestive heart failure due to long history of hypertension, 402.91, 428.40, 428.0 (I11.0, I50.40).

Related posts:

  1. Diseases of the Skin and Subcutaneous Tissue: (ICD-9-CM Chapter 12, Codes 680-709, and ICD-10-CM Chapter 12, Codes L00-L99)
  2. Diseases of the Respiratory System: (ICD-9-CM Chapter 8, Codes 460-519, and ICD-10-CM Chapter 10, Codes J00-J99)
  3. Injuries and E Codes: (ICD-9-CM Chapter 17, Codes 800-995, and External Causes, E800-E999, and ICD-10-CM Chapters 19 and 20, Codes S00-Y99)
  4. Introduction to ICD-10-PCS

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Jun 14, 2017 | Posted by in GENERAL SURGERY | Comments Off on Diseases of the Circulatory System: (ICD-9-CM Chapter 7, Codes 390-459, and ICD-10-CM Chapter 9, Codes I00-I99)

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