Marijuana and Cocaine Use in Young MI Patients Linked to Mortality Risks

One in 10 patients age 50 or younger at the time of first MI have a recent history of cocaine and/or marijuana use, and individuals with this history have worse long-term survival than nonusers, new data show. Given the increasing legalization and use of marijuana, the researchers say more efforts are needed to identify users and convey the seriousness of the cardiovascular risks involved.

“There’s been a lot of data for a long time that cocaine is bad for the heart in various ways and that it is associated with increased mortality, but there is much less data available about marijuana despite its increasing use in the population,” said Ersilia M. DeFilippis, MD (Brigham and Women’s Hospital, Harvard Medical School, Boston, MA), in an interview with TCTMD.

DeFilippis added that the new study is important since so many of the traditional risk factors for MI do not apply to younger patients, making it necessary to delve deeper into the potential causes of their cardiovascular disease and identify better ways of risk stratifying them. But lack of guidance for clinicians on what to tell patients and how to assess their substance abuse is an equally significant problem, she said.

All-Cause Death Risk Highest for Marijuana Users

In the study, published online May 30, 2018, ahead of print in the Journal of the American College of Cardiology, lead investigators DeFilippis and colleague Avinainder Singh, MBBS (Brigham and Women’s Hospital, Harvard Medical School), looked at the records of 2,097 patients age 50 or younger treated for a first MI at two academic hospitals in Massachusetts between 2000 and 2016. Massachusetts voted to legalize marijuana use in 2016. Legal sales of recreational cannabis to those over age 21 will begin there next month.

Cocaine was found in 4.7% of young patients at the time of presentation, and marijuana was documented in 6% by either self-reporting or toxicology testing. Rates of out-of-hospital cardiac arrest were more than twice as high among the substance-abuse group compared with those with no substance abuse. Importantly, this was driven by higher rates among marijuana users (8.8% vs 3.5%; P = 0.007).

Young MI patients who used marijuana or cocaine were less likely than those who did not to have diabetes (14.7% vs 20.4%; P = 0.05) and hyperlipidemia (45.7% vs 60.8%; P < 0.001), and they were more likely to use tobacco (70.3% vs 49.1%; P < 0.001).

Over 11 years of follow-up, substance-use patients had greater all-cause mortality than those with no substance use (18.8% vs 11.3%; P = 0.001), with annual deaths being highest for those who used cocaine. However, after adjusting for age, sex, CV risk factors, medications at discharge, and length of stay, the risk of all-cause death was slightly higher for marijuana (HR 2.09; 95% CI 1.25-3.50) than for cocaine (HR 1.91; 95% CI 1.11-3.29).

Similarly, cardiovascular death was higher among those who used any substance than those who did not (9.4% vs 5.3%; P = 0.01), with annual death rates being highest in cocaine users. After adjustment, risk was higher among cocaine users (HR 2.32 95% CI 1.11-4.85) than in marijuana users (HR 2.13; 95% CI 1.03-4.42).

The study also found that patients with substance abuse were less likely to undergo cardiac catheterization than those with no substance abuse (92.7% vs 96.5%; P = 0.01), driven mainly by the finding that slightly less than 90% of cocaine users had a catheterization compared with 96.4% of nonusers (P = 0.003). Although there were no differences between users and nonusers in rates of PCI, CABG, or thrombolytic therapy, the cocaine group was much less likely to undergo CABG than patients without any substance abuse (3.0% vs 8.8%; P = 0.04).

To TCTMD, DeFilippis said that although the opioid crisis has garnered widespread national attention, the National Institute on Drug Abuse has identified marijuana as the drug that has increased in prevalence most significantly in the last 5 to 10 years.

“There’s so little guidance on what to tell our patients,” DeFilippis observed. “I think what we tried to show here is that when someone presents to a hospital for evaluation for acute coronary syndrome, people tend to ask about tobacco use and cocaine, but . . . broadening that question to include marijuana is important, especially because it’s legal and people might not think to report it without directly being asked.” She added that it’s important for clinicians to make patients feel comfortable enough to be able to talk about their drug use and to explain why the information is needed in prevention efforts.

How Much Do We Really Know?

In an accompanying editorial, Joshua D. Lee, MD, MSc (New York University School of Medicine, New York, NY), and colleagues note that the study did not track continued marijuana use post-MI and say it is “a timely reminder of how little we know about cannabis consumption, cardiovascular disease (CVD), and cannabis’ health effects in general.”

They note that in a 2017 report, the National Academy of Sciences “summarized the evidence as ‘limited’ that acute cannabis smoking is positively associated with an increased risk of acute MI (as a triggering event), and found ‘no evidence to support or refute’ associations between any chronic effects of cannabis use and increased risk of acute MI.” Nevertheless, Lee and colleagues say despite potential benefits for continued use of cannabis in some patients, “we have enough data to recommend reducing or ceasing their intake of inhaled marijuana smoke.”

But the advent of edible marijuana adds a new layer to the problem, as does tackling the problem of how to discourage use of the drug given the “vast uncertainty of the science regarding cannabis and health” and the fact that there are “no proven effective treatments for cannabis use disorders when we do identify them,” they say.

Lee and colleagues raise the issue of alcohol and opioid use, which they point out were not included in the current analysis despite “an increasingly fatal period of opioid-related overdoses in Massachusetts.” Other medical or mental health conditions such as HIV and major depression that might have contributed to death in the years after MI also were not measured, they note.

Importantly, Lee and colleagues observe that inhaled marijuana is on the decline, while edibles, transdermal formulations, and electronic cigarette-like cartridges of cannabis oil are becoming more prevalent. They say more data are needed on health risks in patients using these products.

“This may also provide some opportunities for harm reduction counseling among persistent marijuana smokers, who may well be better off from a cardiovascular standpoint by consuming cannabis edibles,” Lee and colleagues write. “We simply do not know whether this would help, but parallels with continued nicotine replacement therapy or e-cigarette use by former adult smokers are not out of place.”