Progression of Coronary Artery Disease in Non-Ischemic Dilated Cardiomyopathy: An Under-Estimated Phenomenon?

Abstract

Background: Advances in medical therapies for heart failure (HF) have resulted in improvements in survival rates. For patients initially diagnosed with non-ischemic dilated cardiomyopathy (NIDCM), the potential exists for coronary artery disease (CAD) to develop and/or progress over time: 11.4% of patients with non-ischemic/ unknown etiologies in the SOLVD trial were hospitalized for myocardial infarction or angina during the study [Lancet 1992;340:1173–78]. While the time course of and likelihood forCADprogression in non-cardiomyopathy patients has been described [Circulation 1999;100:903–9], little is known about the NIDCM cohort. Therefore, we sought to delineate the magnitude of and risk factors for CAD progression in a NIDCM cohort referred to a tertiary care HF disease management program.Methods: Retrospective chart review of NIDCM cases excluding valvular, peripartum, hypertrophic and restrictive etiologies seen by one practitioner over a 12-month period (Oct. 2001-Sep. 2002). CAD was classified as non-obstructive or obstructive (by RAND criteria [Leape LL et al. CABG: Ratings of appropriateness. p51, Santa Monica CA 1991]) at initial coronary angiography (CA-1); progression was classified on repeat angiography (CA-2) only if obstructive lesions were diagnosed per RAND. In all cases with CAD, the degree of ventricular dysfunction was out of proportion to the severity of obstruction. Differences between patient groups were assessed by chisquare for categorical variables and the Student’s t-test and Kolmogorov-Smirnov test for continuous variables. Results: The cohort consisted of 125 cases (32% new referrals, 37% of all outpatient visits, mean age 45.5 11.8 years, 72% male) of whom 93 underwent CA-1 at a mean of 345 880 days after first HF diagnosis (median 26.0d). CAD of any degree was found in 8 (obstructive in 4; interventions in 3) with a mean age of 58.5 9.6y compared to 46.6 9.8y without any CAD (p 0.01). A history of cigarette smoking and longer duration of HF were associated with CAD at CA-1 (odds ratios 5.8 and 5.6 respectively, p 0.05). 11 patients Impedance Cardiography: A Comparison of Cardiac Output Versus Waveform Analysis for Assessing Left Ventricular Systolic Dysfunction Arthur P. DeMarzo, Russell F. Kelly, James E. Calvin2—Dermed Diagnostics Inc, Wheaton, IL; Division of Adult Cardiology, Cook County Hospital, Chicago, IL