Cocaine addicts who otherwise appeared to have healthy hearts showed significant cardiac damage when under the watchful eye of cardiovascular magnetic resonance (CMR) imaging, an Italian team has found.
The study, published online in the June 20 edition of the journal Heart, put 25 men and five women (average age 39) through a comprehensive lab, clinical and instrumental assessment, including B-type natriuretic peptide and troponin I assay, echocardiography, exercise stress test and a 24-hour ECG recording. They also underwent CMR imaging using a 1.5 Tesla scanner. Myocardial edema was evaluated by a T2-weighted STIR sequence, and fibrosis was observed using the late gadolinium enhancement technique.
The subjects had no history of heart disease or its symptoms; the evaluation was done 48 hours after the withdrawal of cocaine. The group was comprised of heavy users, having consumed an average of 5.5 grams of cocaine a day for 12 years, with 16 addicts admitting to using other substances including heroin and alcohol.
Lead author Giovanni Donato Aquaro and colleagues found biomarkers indicating cardiac involvement in just one of the 30 participants. Half the subjects had subtle abnormalities at resting ECG. Exercise stress testing and Holter studies found no ischemic or arrhythmic events. Echocardiography provided evidence of wall motion abnormalities in 12 subjects.
But CMR evaluation told a different story. Heart muscle had been damaged in 25 subjects (83 percent); there was edema in 14 (47 percent); and fibrosis in 22 patients (73 percent). Eleven subjects (37 percent) showed both myocardial edema and fibrosis, nine of them with similar localizations. Seven subjects had ischemic patterns of fibrosis, and 15 had non-ischemic patterns of fibrosis, the authors reported.
There are roughly 6.4 million users between the ages of 15 and 64 in the U.S. alone, the researchers noted, and cocaine use has been associated a quarter of nonfatal myocardial infarctions among those under 45 years.