Cardiac implications of thrombotic thrombocytopenic purpura

Abstract

Thrombotic thrombocytopenic purpura (TTP) is a multisystem disorder that essentially can affect any organ in the human body. The hallmark of the pathogenesis in TTP is the large von Willebrand factor multimers on platelet-mediated micro-thrombi formation, leading to microvascular thrombosis. Autopsy studies showed that cardiac arrest and myocardial infarction are the most common immediate causes of death in these patients. Clinical manifestations of cardiac involvement in TTP vary dramatically, from asymptomatic elevation of cardiac biomarkers, to heart failure, MI and sudden cardiac death. There is limited knowledge about optimal cardiac evaluation and management in patients with TTP. The absence of typical cardiac symptoms, combined with complicated multi-organ involvement in TTP, may contribute to the under-utilization of cardiac evaluation and treatment. Prompt diagnosis and timely initiation of effective therapy could be critically important in selected cases. Based on our experience and this review of the literature, we developed several recommendations for focused cardiac evaluation for patients with acute TTP: (1) patients with suspected or confirmed TTP should be screened for the potential presence of cardiac involvement with detailed history and physical, electrocardiogram and cardiac enzymes; (2) clinical deterioration of TTP patients warrants immediate cardiac reevaluation; (3) TTP patients with clinical evidence of cardiac involvement should be monitored for telemetry, cardiac biomarkers and evaluated with transthoracic echocardiography. These patients require urgent targeted TTP treatment as well as cardiac-specific treatment. Aspirin therapy is indicated for all TTP patients. Since epicardial coronary artery involvement is rare, cardiac catheterization is usually not required, given the high risk for hemorrhage and kidney injury; (4) we recommend evidence-based medical therapy for ischemic symptoms and heart failure. TTP patients with evidence of cardiac involvement would also benefit from routine cardiology follow up during remission.

Keywords: ADAMTS13; Acute myocardial infarction; Anti-platelet therapy; Coronary artery disease; Thrombotic thrombocytopenic purpura; von Willebrand factor.

Figure 1

Recommendations on clinical assessment and management of cardiac involvement of thrombotic thrombocytopenia purpura. All patients with a diagnosis of thrombotic thrombocytopenia purpura (TTP) should be given low dose aspirin daily and screened for cardiac involvement by clinical cardiac symptoms, cardiac biomarkers (cardiac troponin, B-type natriuretic peptide etc) and electrocardiogram. Positive screen of cardiac involvement of TTP predicts adverse outcome, requiring further evaluation and treatment as recommended above. TTP: Thrombotic thrombocytopenia purpura; cTn, Cardiac troponin; BNP: B-type natriuretic peptide; ECG: Electrocardiogram; ACEi: Angiotensin converting enzyme inhibitors; ARB: Angiotensin receptor blockers; LVAD: Left ventricular assist device; ECMO: Extracorporeal membrane oxygenation.