Faculty Bibliography

BACKGROUND:There is controversy about preferred methods to relieve obstruction in hypertrophic cardiomyopathy patients still symptomatic after β-blockade or verapamil. METHODS AND RESULTS/RESULTS:Of 737 patients prospectively registered at our institution, 299 (41%) required further therapy for obstruction for limiting symptoms, rest gradient 61 ± 45, provoked gradient 115 ± 49 mm Hg, and followed up for 4.8 years. Disopyramide was added in 221 (74%) patients and pharmacological control of symptoms was achieved in 141 (64%) patients. Overall, 138 (46%) patients had surgical relief of obstruction (91% myectomy) and 6 (2%) alcohol septal ablation. At follow-up, resting gradients in the 299 patients had decreased from 61 ± 44 to 10 ± 25 mm Hg (P<0.0001); New York Heart Association class decreased from 2.7 ± 0.7 to 1.8 ± 0.5 (P<0.0001). Kaplan-Meier survival at 10 years in the 299 advanced-care patients was 88% and did not differ from nonobstructed patients (P=0.28). Only 1 patient had sudden death, a low annual rate of 0.06%/y. Kaplan-Meier survival at 10 years in the advanced-care patients did not differ from that expected in a matched cohort of the US population (P=0.90). CONCLUSIONS:Patients with obstruction and symptoms resistant to initial pharmacological therapy with β-blockade or verapamil may realize meaningful symptom relief and low mortality through stepped management, adding disopyramide in appropriately selected patients, and when needed, by surgical myectomy.

BACKGROUND: Left ventricular (LV) outflow tract obstruction (LVOTO) is most commonly seen in patients with hypertrophic cardiomyopathy. Postexercise dynamic LVOTO (DLVOTO) has been infrequently identified in symptomatic patients without LV hypertrophy, and its pathophysiology is not well established. The aim of this study was to identify echocardiographic abnormalities that might explain the dynamic development of systolic anterior motion, mitral-septal contact, and LVOTO in these patients. METHODS: Patients with DLVOTO and normal wall thickness were compared with 20 age-matched and gender-matched controls with normal stress echocardiographic findings. Two other groups were also compared: patients with DLVOTO and mild segmental hypertrophy (segmental wall thickness /=5 mm. CONCLUSIONS: DLVOTO after exercise can occur in the absence of LV hypertrophy and may be associated with high gradients and cardiac symptoms. Elongated, redundant mitral valve leaflets with anterior position of the papillary muscles appear to cause the postexercise obstruction.

Patients with coexisting hypertrophic cardiomyopathy (HC) and hypertension present diagnostic and therapeutic dilemmas. A retrospective cohort study of patients with HC with coexisting hypertension referred to a specialized HC program was conducted. HC and hypertension were confirmed by strict criteria. Echocardiographic data were reviewed for peak instantaneous left ventricular outflow tract gradients, at rest and with provocation. Symptom control, left ventricular outflow tract gradients, and hypertension control were compared between the first and last visits. One hundred fifteen patients (94 obstructed and 21 nonobstructed) met the eligibility criteria for the study and were included in the analysis, with the mean follow-up duration of 36 months. Because of the treatment strategy, there was a significant decrease in the number of patients treated with direct vasodilators and an increase in the use of beta blockers and disopyramide. Twenty-one obstructed patients (22%) required septal reduction therapy. Overall, in obstructed patients, peak instantaneous left ventricular outflow tract gradient at rest decreased from 48 to 14 mm Hg (p <0.01), which was accompanied by significant improvement in functional class (2.4 vs 1.8, p <0.01). The prevalence of uncontrolled hypertension decreased from 56% at the initial visit to 37% at the last visit (p = 0.01). The cohort had a low rate of adverse cardiovascular outcomes such as death, acute coronary syndromes, and stroke. In conclusion, the present study demonstrates that stepwise, symptom-oriented therapy is feasible and effective in patients with coexisting HC and hypertension.