Abstract 3600: Identification of Hypertrophic Cardiomyopathy in the Community and the Value of Preparticipation Sports Examinations
Introduction. Although the hypertrophic cardiomyopathy (HCM) phenotype occurs in 1 of 500 adults in the general population, most cardiology practices comprise relatively few HCM patients, suggesting that many affected individuals evade clinical recognition.
Hypothesis. The circumstances under which HCM is identified clinically will provide clues to this under-diagnosis.
Methods. We analyzed the clinical triggers leading to the diagnostic echocardiogram in 711 HCM patients. Ages were 41±21; 63 % were male.
Results. Most commonly, in 384 patients (54%), HCM was first suspected by the onset of new cardiac symptoms or after acute cardiac events, including 7 who presented with cardiac arrest. A minority of patients (327; 46%) were recognized while asymptomatic, including 225 (32%) by routine medical evaluations of which 27 (4%) came to recognition by preparticipation examinations for sports or other activities. Women were more likely to be suspected of HCM by virtue of symptoms or acute events (64% vs. 48% for men; p<0.0001), and least commonly by routine medical evaluations (20% vs. 38% for men; p<0.0001). Also older patients (≥50 years) and those with outflow obstruction (gradient ≥30 mmHg at rest) were more often diagnosed because of symptoms or acute cardiac events (71% vs. 45% for younger patients; p<0.0001 and 61% vs. 52%; for nonobstructive; p=0.04). In contrast, patients with extreme left ventricular hypertrophy (wall thickness ≥30 mm) and those judged to be at high risk of sudden death were more often asymptomatic and identified by routine or family screening examinations (52% vs. 29% for lesser hypertrophy; p<0.0001 and 19% vs. 11% for low risk patients; p=0.008).
Conclusions. An important minority of HCM patients are identified while asymptomatic, often fortuitously, and by virtue of routine or preparticipation sports examinations. However, most HCM patients continue to be diagnosed only after recognition of overt clinical manifestations, such as cardiac symptoms or events.