Cocaine and Marijuana Use Among Young Adults With Myocardial Infarction

Abstract

Background: Substance abuse is increasingly prevalent among young adults, but data on cardiovascular outcomes remain limited.

Objectives: The objectives of this study were to assess the prevalence of cocaine and marijuana use in adults with their first myocardial infarction (MI) at ≤50 years and to determine its association with long-term outcomes.

Methods: The study retrospectively analyzed records of patients presenting with a type 1 MI at ≤50 years at 2 academic hospitals from 2000 to 2016. Substance abuse was determined by review of records for either patient-reported substance abuse during the week before MI or substance detection on toxicology screen. Vital status was identified by the Social Security Administration's Death Master File. Cause of death was adjudicated using electronic health records and death certificates. Cox modeling was performed for survival free from all-cause and cardiovascular death.

Results: A total of 2,097 patients had type 1 MI (mean age 44.0 ± 5.1 years, 19.3% female, 73% white), with median follow-up of 11.2 years (interquartile range: 7.3 to 14.2 years). Use of cocaine and/or marijuana was present in 224 (10.7%) patients; cocaine in 99 (4.7%) patients, and marijuana in 125 (6.0%). Individuals with substance use had significantly lower rates of diabetes (14.7% vs. 20.4%; p = 0.05) and hyperlipidemia (45.7% vs. 60.8%; p < 0.001), but they were significantly more likely to use tobacco (70.3% vs. 49.1%; p < 0.001). The use of cocaine and/or marijuana was associated with significantly higher cardiovascular mortality (hazard ratio: 2.22; 95% confidence interval: 1.27 to 3.70; p = 0.005) and all-cause mortality (hazard ratio: 1.99; 95% confidence interval: 1.35 to 2.97; p = 0.001) after adjusting for baseline covariates.

Conclusions: Cocaine and/or marijuana use is present in 10% of patients with an MI at age ≤50 years and is associated with worse all-cause and cardiovascular mortality. These findings reinforce current recommendations for substance use screening among young adults with an MI, and they highlight the need for counseling to prevent future adverse events.

Keywords: cocaine; marijuana; myocardial infarction; substance abuse; young adults.

FIGURE 1. Trends in Substance Use Over Time

Trends in (A) cocaine and (B) marijuana use over the course of the study period, 2000 to 2016. The thick dashed line represents a fitted regression Line and the thinner dashed lines are confidence intervals. MI = myocardial infarction. Triangles represent the percentage of patients with MI for the particular year who used cocaine. Asterisks represent the percentage of patients with MI for the particular year who used marijuana.

FIGURE 2. All-Cause Mortality and Cardiovascular Mortality in Patients With Substance Abuse

Kaplan-Meier curves of (A) all-cause mortality and (B) cardiovascular mortality in patients with substance abuse compared with patients without substance abuse. HR = hazard ratio.

FIGURE 3. Annual Incidence Rates for All-Cause Death and Cardiovascular Death

Observed annual death and cardiovascular death rates are shown by drug of abuse in 100 person-years.

FIGURE 4. All-Cause Mortality and Cardiovascular Mortality Stratified by Use of Cocaine or Marijuana

Kaplan-Meier curves of (A) all-cause mortality and (B) cardiovascular mortality by drug of abuse.

FIGURE 5. Adjusted Cardiovascular Mortality and All-Cause Death

Forest plots are shown for adjusted models of all-cause and cardiovascular (CV) death. AU-cause death was adjusted for age, sex, presence of diabetes, hypertension, peripheral vascular disease, smoking, high-density lipoprotein cholesterol, triglycerides, revascularization, creatinine, medications at discharge, and length of stay. CV death was adjusted for age, presence of diabetes, hypertension, peripheral vascular disease, smoking, high-density lipoprotein cholesterol, creatinine, medications at discharge, and length of stay. Adj. HR = adjusted hazard ratio; CI = confidence interval.

CENTRAL ILLUSTRATION. Cocaine and Marijuana Use in Young Patients With Myocardial Infarction

We found that in our young patients with myocardial infarction (MI), approximately 10% were using either cocaine or marijuana. Cocaine use increases myocardial oxygen demand, decreases oxygen supply, and accelerates atherosclerosis and can create a prothrombotic state. Marijuana use leads to the generation of reactive oxygen species, decreases myocardial contractility, and leads to neointimal proliferation of vascular smooth muscle cells. Substance abuse was associated with increased all-cause mortality and cardiovascular mortality.