Hypertrophic obstructive cardiomyopathy in rheumatoid arthtritis – coincidence or association? A case report

Abstract

A 60-year-old woman with a history of rheumatoid arthritis was admitted to the hospital for investigation of dyspnea on exertion (New York Heart Association class II), polyarthralgias and mild fever. An echocardiogram revealed asymmetric hypertrophy of the interventricular septum with signs of subaortic obstruction.

The coexistence of rheumatoid arthritis and hypertrophic cardiomyopathy could be connected with the human lymphocyte antigen DR4, which is common in both conditions. Further studies are necessary to assess whether a true association of the above diseases exists.

Rheumatoid arthritis (RA) is a chronic autoimmune multisystemic disease that can affect the pericardium, myocardium and endocardium. Heart involvement is a frequent cause of death (1–3).

On the other hand, hypertrophic cardiomyopathy (HCM) is usually familial with an autosomal dominant transmission.

The present article is the first report of hypertrophic obstructive cardiomyopathy in a patient with RA. It would be interesting to determine whether a linkage between HCM and RA can be demonstrated.

CASE PRESENTATION

A 60-year-old woman with a known history of RA was admitted to Laiko General Hospital of Athens (Athens, Greece) due to dyspnea on exertion (New York Heart Association class II), polyarthralgias and mild fever. RA was diagnosed three years previously on the basis of clinical and laboratory findings (4). The patient was given nonsteroidal anti-inflammatory drugs, and three months before admission, corticosteroids (7.5 mg prednisone daily) were started because of pleuritis.

On physical examination, her heart rate was 86 beats/min and her blood pressure was 130/85 mmHg. On auscultation, a fourth heart sound and an ejection systolic murmur, best heard at the left sternal border radiating toward the aortic and mitral areas, was revealed. Laboratory findings were as follows: hematocrit 30%, white blood cell count 12.83×10⁹/L, platelet count 350×10⁹/L, urea 10.65 mmol/L, creatinine 114.92 μmol/L, serum glutamic oxaloacetic transaminase 41 U/L, serum glutamic pyruvate transaminase 25 U/L, erythrocyte sedimentation rate 72 mm/h and CRP 13.4 mg/L. She was seropositive for rheumatoid factor with a titre of 1:70.

A resting electrocardiogram showed left anterior bundle branch block. Transthoracic echocardiography demonstrated asymmetric hypertrophy of the interventricular septum (16 mm), systolic anterior movement of the anterior mitral valve leaflet and a dynamic subaortic gradient of 64 mmHg (Figure 1). These findings are consistent with hypertrophic obstructive cardiomyopathy. The ejection fraction was 62%. There was no family history of HCM or sudden death. The patient received methotrexate in combination with steroids for the arthritis as well as verapamil 80 mg three times daily for the HCM. Her symptoms were relieved but the subaortic gradient decreased to 34 mmHg.

Figure 1).

Two-dimensional echocardiographic image from the parasternal long-axis view of the patient’s left ventricle showing interventricular septum hypertrophy (left), and M-mode showing the systolic anterior movement (SAM) of the mitral valve leaflet (right)

DISCUSSION

RA is a common chronic autoimmune disease involving many organ systems, primarily the joints. It is frequently accompanied by cardiac lesions in the pericardium, myocardium and endocardium, comprising coronary arteries, valvular tissue and the conduction system. Heart involvement in RA is the leading cause of death (1–3).

HCM is usually familial with autosomal dominant transmission and a high degree of penetrance, although there are sporadic episodes of nonhereditary transmission due to genetic mutation. In familial HCM, 10 gene abnormalities have been discovered in the sarcomere, ie, the genes of beta cardiac myosin heavy chain, cardiac troponin T, alpha-tropomyosin, cardiac myosin-binding protein C, essential or regulatory myosin light chain, cardiac troponin I and C, alpha-cardiac actin and titin (5,6). Gene penetrance is often age-related, with clinical features typically developing during adolescence (5).

Previous studies have found that the transmission of HCM seems to be associated with the human lymphocyte antigen (HLA). However, other reports (7) could not verify this association. HCM can be divided into two subtypes: a familial form linked to the HLA system, which may be related to the obstructive type, and a sporadic form not linked to HLA antigens. The HLA system may be a possible link between HCM and RA because this HLA phenotype (ie, HCM) is common in the latter condition (7–10). Consequently, the coexistence of HCM and RA is possibly connected with HLA-DR4, which is commonly found in both conditions (8).

It should be noted that the patient had no history of arterial hypertension or renal involvement, conditions associated with left ventricular hypertrophy. Moreover, the short duration of steroid use and its low dose are highly unlikely to be the cause her left ventricular hypertrophy.

Several case reports on connective tissue diseases, such as systemic sclerosis, systemic lupus erythematosus and polyarteritis nodosa, are associated with HCM (11–16). Furthermore, in a female patient with Felty’s (RA, splenomegaly, neutropenia, and on occasion, anemia and thrombocytopenia) and Sjogren’s syndromes, hypertrophic obstructive cardiomyopathy have been found (17).

With the current advances in molecular biology, it would be interesting to determine whether a linkage exists between HCM and RA on a genetic level. This association, however, may be a random occurrence.