Should all patients with dilated cardiomyopathy receive chronic anticoagulation?

Left ventricular thrombus and subsequent thromboembolism in patients with severe systolic dysfunction

STUDY OBJECTIVES

To determine the frequency of left ventricular (LV) thrombi by echocardiography and to define the predictors of LV thrombus and subsequent thromboembolism.

DESIGN

Retrospective case-control design.

SETTING

Single tertiary care center.

PATIENTS

Twenty-eight patients with LV thrombus in a consecutive series of 144 patients with severe LV dysfunction and follow-up period for a mean of 27.6 months.

MEASUREMENTS AND RESULTS

Thirty-five clinical and echocardiographic variables were evaluated. The mean age of patients with (n = 28) vs patients without (n = 116) LV thrombus was 50.3 +/- 11.0 years vs 54.2 +/- 11.1 years (p = 0.09), with 22 patients (78.6%) and 78 patients (67.2%) being male (p = 0.24), respectively. The mean ejection fraction (EF) for those with vs those without LV thrombus was 17.5 +/- 5.5 vs 20.0 +/- 6.9 (p = 0. 08), with 16 patients (57.1%) and 42 patients (36.2%) having an EF < 20% (p = 0.04), respectively. The groups were similar with respect to other baseline characteristics, comorbid illnesses, and drug therapies other than anticoagulants. All 28 patients with LV thrombus (100%) and 54 of those without LV thrombus (46.6%) were treated with warfarin. Ischemic etiology of the cardiomyopathy (odds ratio, 4.78; 95% confidence interval, 1.51 to 15.11; p = 0.008) and increased LV internal diastolic dimension (LVIDD; odds ratio, 1.10; 95% confidence interval, 1.03 to 1.18; p = 0.004) were found to be independent predictors of thrombus formation. Peripheral embolism occurred in 5 patients (17.9%) vs 13 patients (11.2%) of those with and without LV thrombi, respectively (p = 0.35). Ischemic etiology of the cardiomyopathy (odds ratio, 3.79; 95% confidence interval, 1. 13 to 12.64; p = 0.03) and EF (odds ratio, 0.91; 95% confidence interval, 0.82 to 1.00; p = 0.04) were found to be independent predictors of systemic embolization. The patients with an embolic event suffered a significantly higher mortality (7 of 18 patients; 38.9%) during the follow-up period when compared to those without an embolic event (13 of 126 patients; 10.3%; p < 0.0001).

CONCLUSIONS

We conclude that ischemic cardiomyopathy and dilated LV chamber sizes (LVIDD > 60 mm) are independently associated with LV thrombi. A peripheral embolic event is related to poor long-term survival in this patient group.

Anticoagulation in Congestive Cardiomyopathy: Steps Toward Defining the Great Unknown

It is generally agreed that congestive cardiomyopathy predisposes to the formation of cardiac thrombus and in turn systemic thromboembolism. Several uncontrolled studies have confirmed this association and have prompted wide-scale recommendations for long-term anticoagulation in these patients. Clinical studies have also attempted to identify patients at high risk for embolic events. The presence of cardiac thrombus, its topographic characteristics, the severity of left ventricular dysfunction, and decreased apical flow velocities may each represent markers of increased risk.Driven by the lack of definitive data addressing this issue, several pleas from the medical community have come forth for a large, randomized controlled trial of anticoagulation in congestive cardiomyopathy. Accordingly, a multicenter trial comparing aspirin, warfarin, or placebo as prophylaxis against thromboembolism has been proposed and if conducted will provide valuable information regarding the management of patients with congestive cardiomyopathy.