Abstract 17593: Long-term Clinical Follow-up Results of Patients With Apical Hypertrophic Cardiomyopathy
Background: Apical hypertrophic cardiomyopathy (AHC) is relatively common in the Asian countries and there have been limited data about the long-term clinical course of disease.
Methods: The study cohort included a total 413 patients (297 males, age 59±12 years) who were diagnosed to have AHC between Jan 2000 and Mar 2012 in our institution. Their changes in ECG and echocardiographic were analyzed with clinical outcomes.
Results: Mean follow-up duration was 55.4±36.6 months. Follow-up ECG showed decrease in mean T wave inversion (from 12.3±6.5 to 9.2±5.1 mV, p<0.001), R wave amplitude (from 38.0±11.3 to 30.7±11.3 mV, p<0.001), and ST segment depression (from 2.0±1.4 to 1.1±1.2 mV, p<0.001) with significant increase of QRS duration (from 95.5±12.1 to 101.5±18.6 ms, p=0.02) and corrected QT interval (from 441.5±31.2 to 461.1±22.4 ms, p=0.002). Follow-up echocardiography showed increase in LV diastolic diameter (p<0.001), LA diameter (p=0.023), LV end-diastolic volume (p=0.005), and tricuspid regurgitation Vmax (from 1.7±1.2 to 2.5±0.8 m/s, p<0.001). Apical aneurysm was documented in 2 among 119 patients up to 5 years follow-up and in another one among 34 patients up to 10 years follow-up. Overall cardiovascular mortality was 2.1% during 10-year clinical follow-up and adverse cardiac events (death, stroke, development of atrial fibrillation [Af], acute coronary syndrome [ACS], and hospitalization due to heart failure) developed in 18.5%. The most common morbidity was new onset Af (10.5%) and ischemic stroke (9.5%), which showed parallel cumulative increase during follow-up. ACS and hospitalization developed in 6.5% and 4.5%, respectively. Initial TR Vmax ≥3 m/s was the only imaging variable associated with development of clinical events (HR= 4.9, 95% CI = 2.1 - 11.2, p<0.001).
Conclusions: Steady increase in development of clinical events was characteristic and progressive chamber enlargement leading to Af seems to be a main mechanism of clinical deterioration.
- © 2013 by American Heart Association, Inc.