Overdiagnosis of Left Ventricular Noncompaction

Abstract

Introduction: Left ventricular noncompaction (LVNC) is characterized by prominent left ventricular trabeculations and deep intertrabecular recesses, and is classically described as carrying a grave prognosis. Common clinical characteristics include young age, risk of systemic thromboembolism, ventricular arrhythmias, and inexorable progression toward death or transplantation. The goal of this study was to identify all cases of LVNC and ‘prominent trabeculation’ (TRN) diagnosed at our institution over a ten year period, and to attempt to validate the diagnoses. Hypothesis: As improved echocardiographic technology has allowed for easier identification of ventricular trabeculae, LVNC and TRN are being overdiagnosed. Methods: Echocardiography reports from 1999–2009 at our institution with TRN and/or LVNC were termed “positive,” and any reports without notation of TRN and/or LVNC in this cohort of patients were termed “negative.” In addition, we reviewed all charts for concomitant cardiac MRIs and cardiac transplant status. We evaluated a) the consistency with wich LVNC or TRN were noted on echocardiograms on the same patients, and b) concordance with other diagnostic modalities (cardiac MRI and pathology from explanted hearts). Results: 709 patients had a total of 1428 echocardiograms, of which 1015 were positive. 71% of the cohort was male (n = 505), and the average age was 61 years. 19% of positive echocardiograms (n = 1015) occurred in patients with relatively preserved systolic function (LVEF > 45%). Out of 466 patients (66% of the cohort) with repeat echocardiograms during the time period studied, 12% had consistently positive repeat echocardiograms, 63% had consistently negative repeat echocardiograms, and 25% had a mixture of positive and negative echocardiograms. Out of 48 patients who subsequently underwent cardiac transplantation, only 3 (6%) had TRN or LVNC confirmed on pathology review. Of 51 patients who underwent cardiac MRI, 8 (16%) confirmed the presence of TRN or LVNC. Conclusion: In our study cohort, there was little reproducibility for a diagnosis of LVNC or TRN by echocardiography, and very little correlation with findings on cardiac MRI or pathology. In addition, the clinical characteristics of the study population were very distinct from the classical description of patients with LVNC. Given the clinical and psychological ramifications of labeling a patient with these diagnoses, we urge reconsideration of the diagnostic criteria.