Clinicopathological profiles of progressive heart failure in hypertrophic cardiomyopathy.

AIMS: Hypertrophic cardiomyopathy (HCM) is an important cause of heart failure-related disability over a wide range of ages. Profiles of severe progressive heart failure symptoms and death, or heart transplantation deserve more complete definition within large patient cohorts. METHODS AND RESULTS: Clinical and morphological features of heart failure were assessed in 293 consecutive HCM patients over a median follow-up of 6 (inter-quartile range 2-11) years. Gross and histopathological features were analysed in 12 patients for whom the heart was available for inspection. Of the 293 patients, 50 (17%) developed severe progressive heart failure, including 18 who died or were transplanted. Three profiles of heart failure were identified predominantly associated with: (i) end-stage systolic dysfunction (ejection fraction <50%) (15; 30%); (ii) left ventricular (LV) outflow obstruction at rest (11; 22%); and (iii) non-obstructive with preserved systolic function (24; 48%). Overall, atrial fibrillation (AF) contributed to heart failure in 32 patients (64%) among the three profiles. Compared with other patients, those non-obstructive with preserved systolic function had earlier onset of heart failure symptoms mainly due to diastolic dysfunction, and the most accelerated progression to advanced heart failure and adverse outcome (P = 0.04). Thrombi were identified in the left atrial appendage of five gross heart specimens all belonging to patients with AF, including three of which were unrecognized clinically and had previously embolized. Extensive myocardial scarring with LV remodelling was evident in all end-stage patients; no or only focal scars were present in other patients. CONCLUSION: Profiles of advanced heart failure in HCM are due to diverse pathophysiological mechanisms, including LV outflow obstruction and diastolic or global systolic ventricular dysfunction. Atrial fibrillation proved to be the most common disease variable associated with progressive heart failure. Recognition of the heterogeneous pathophysiology of heart failure in HCM is relevant, given the targeted management strategies necessary in this disease.

Cardiovascular magnetic resonance signs of ischemia in hypertrophic cardiomyopathy.

BACKGROUND: Recurrent myocardial ischemia has been recognized as playing an important role in the pathophysiology of hypertrophic cardiomyopathy (HCM) and cardiovascular magnetic resonance (CMR), with or without gadolinium, is a promising method of evaluating fibrosis, edema and hypoperfusion. The aim of this study is to evaluate the interrelationship between late enhancement (LE) and other signs of ischemia, such as edema and perfusion defects, and to relate them to clinical data in order to describe the stage of the disease. METHODS: Forty-four patients were evaluated by CMR cine images, T2-weighted sequences for edema and LE sequences. First-pass perfusion study was obtained in 37 patients. Acute-subacute ischemic events were clinically defined as the presence of chest pain or new onset of ST-segment depression, end-stage phase by left ventricular ejection fraction <50% and maximal left ventricular wall thickness <25 mm. RESULTS: Intramural patchy LE was found in 35/44 (80%) patients; extensive LE in 4/44 (9%). Edema was present in 24/44 (54%) patients and perfusion defects in 17/37 (46%). Simultaneous presence of patchy LE, edema and hypoperfusion in corresponding segments, was significantly associated to acute-subacute ischemic-phase parameters (p=0.02; RR 1.99, 95% C.I. 0.77-5.02). Extensive LE and perfusion defects in the absence of edema were significantly related to end-stage HCM (p<0.001; RR 13.7, 95% C.I. 1.83-102.05). CONCLUSIONS: Using CMR in patients with HCM, we found focal tissue abnormalities consistent with regional ischemia at various stages. CMR provides important, clinically relevant information on the acuity, extent and functional relevance of ischemic injuries in HCM.