Effects of Cocaine and/or Heroin Use on Resting Cardiovascular Function

Background: Regular cocaine and/or heroin use is associated with major health risks, especially cardiovascular disease (CVD), but confounded by other factors. Objectives: We examined effects of chronic (years of regular use) and recent (past-month) use of cocaine and heroin, controlling for other factors, on resting cardiovascular function. Methods: In a sample of cocaine and/or heroin users (N=292), we obtained data on demographics, body mass index (BMI), history of substance use, and electrocardiogram, heart rate (HR) and blood pressure (BP). Following bivariate correlations, three-block (1: demographics, BMI; 2: tobacco, alcohol, marijuana; 3: cocaine, heroin) regression analyses were conducted to predict cardiovascular measures. Results: Higher BMI predicted increased systolic and diastolic BP (as did older age), increased supine HR, and longer QRS duration, QTc interval, PR interval, and P-wave duration. Recent substance use had more reliable effects than chronic use on cardiovascular measures. Past-month marijuana-use days predicted higher systolic BP, lower supine HR, and greater likelihood of early repolarization and ST elevation, whereas average daily marijuana use predicted shorter QTc interval. Average daily alcohol use predicted higher diastolic BP, higher supine HR and lower likelihood of sinus bradycardia (HRbpm). Past-month tobacco-use days predicted shorter QTc interval and increased likelihood of profound bradycardia (HRbpm). Past-month heroin-use days predicted lower seated HR, greater likelihood of sinus bradycardia and lower likelihood of left ventricular hypertrophy. More years of regular cocaine use and past-month cocaine-use days predicted longer QTc interval. Conclusions: Cocaine and heroin incrementally predicted modest variance in resting bradycardia and QTc interval. Clinicians should first consider demographics and recent use of tobacco, alcohol and marijuana before assuming cocaine and heroin affect these measures