Long-term follow-up of 34 adults with isolated left ventricular noncompaction: A distinct cardiomyopathy with poor prognosis

OBJECTIVES We sought to describe characteristics and outcome in adults with isolated ventricular noncompaction (IVNC). BACKGROUND Isolated ventricular noncompaction is an unclassified cardiomyop athy due to intrauterine arrest of compaction of the loose interwoven meshw ork Knowledge regarding diagnosis, morbidity and prognosis is limited. METHODS Echocardiographic criteria for IVNC include-in the absence of signi ficant heart lesions-segmental thickening of the left Ventricular myocardia l wall consisting of two layers: a thin, compacted epicardial and an extrem ely thickened endocardial layer with prominent trabeculations and deep rece sses. Thirty-four adults (age greater than or equal to 16 years, 25 men) fu lfilled the diagnostic criteria and were followed prospectively. RESULTS At diagnosis, mean age was 42 +/- 17 years, and 12 patients (35%) w ere in New York Heart Association class III/IV. Left ventricular end-diasto lic diameter nas 65 +/- 12 mm and ejection fraction 33 +/- 13%. Apex and/or midventricular segments of both the inferior and lateral wall were involve d in >80% of patients. Follow-up nas 44 +/- 40 months. Major complications were heart failure in 18 patients (53%), thromboembolic events in 8 patient s (24%) and ventricular tachycardias in 14 patients (41%). There were 12 de aths: sudden in six, end-stage heart failure in four and other causes in tw o patients. Four patients underwent heart transplantation. Automated cardio verter/defibrillators were implanted in four patients. CONCLUSIONS Diagnosis of IVNC by echocardiography using strict criteria is feasible. Its mortality and morbidity are high, including heart failure, th rombo-embolic events and ventricular arrhythmias. Risk stratification inclu des heart failure therapy, oral anticoagulation, heart transplantation and implantation of an automated defibrillator/cardioverter. As IVNC is a disti nct entity, its classification as a specific cardiomyopathy seems to be mor e appropriate. (C) 2000 by the American College of Cardiology.