Author + information
- Ersilia M. DeFilippis, MD,
- Avinainder Singh, MBBS,
- Deepak L. Bhatt, MD, MPH and
- Ron Blankstein, MD∗ ()
- ↵∗Brigham & Women’s Hospital, 75 Francis Street, Boston, Massachusetts 02115
We recently reported the results of the YOUNG-MI (Cocaine and Marijuana Use Among Young Adults With Myocardial Infarction) registry focusing on cocaine and/or marijuana use in patients presenting with a first myocardial infarction at or below the age of 50 years (1). We found that cocaine and marijuana were both independently associated with increased cardiovascular and all-cause mortality. We read with interest the 2 letters to the editor in this issue by Dr. Rana and colleagues and Dr. Chrétien and colleagues.
Dr. Rana and colleagues astutely mention that smoking is an important potential interaction with marijuana use, as many individuals have had much longer duration and frequency of tobacco smoking compared with cannabis. They suggest that a multivariable model may not provide an accurate assessment of risk.
When our analyses were stratified by smoking status, we found that among smokers, both cocaine and marijuana use remained associated with increased all-cause and cardiovascular death. However, because nonsmokers had a significantly lower overall event rate, we were underpowered to assess the association of substance abuse and cardiovascular outcomes in this cohort.
Given these additional analyses, our conclusions regarding all-cause and cardiovascular mortality among patients with cannabis use should not be significantly affected. Nevertheless, it is important that counseling regarding cannabis and cocaine use also include counseling regarding tobacco cessation, as their concomitant use is common.
Dr. Chrétien and colleagues inquired regarding the use of toxicological screening for identifying patients with cocaine and/or marijuana use. Cocaine and/or marijuana users in our cohort were detected either by patient-reported use within 7 days of myocardial infarction or by toxicology screening. Of the 2,097 patients in our cohort, 676 had toxicology screening with 176 (26%) having a positive test for cocaine and/or marijuana. In contrast, the number of patients that were identified as substance users by history alone was much smaller, and given the retrospective design of our study, a positive history of drug use might have informed the toxicology screen and vice versa.
While we agree that toxicological screening is the most effective way to assess substance abuse, it is important to recognize that there are pitfalls on relying entirely on toxicological screening. Immunoassays are often subject to cross-reactivity with structurally related compounds and can have false-positive results. Case reports have also identified false-positive results for cannabinoids with ibuprofen, naproxen, and other agents (2).
We had also aimed in our original study to examine nonprescription opioid use in our population, given the opioid epidemic and high rates of coingestion in this population. However, there was significant confounding of patients who had received morphine in the emergency room, and we could not meaningfully distinguish prescription opioid use from nonprescription opioid use.
Therefore, the results of screening tests should be used to prompt providers to have a discussion with patients about drug use and should not be interpreted in isolation.
We realize that the rate of cocaine and/or marijuana use in our population is still underestimated even with the use of toxicology screening, as it was only performed at the discretion of the ordering provider. We hope that these results will prompt more providers to ask about drug use when evaluating young patients with myocardial infarction and consider toxicology screening as adjunctive testing.
Please note: Dr. Bhatt has served on the advisory board of Cardax, Elsevier Practice Update Cardiology, Medscape Cardiology, and Regado Biosciences; has served on the board of directors of Boston VA Research Institute, Society of Cardiovascular Patient Care, and TobeSoft; has served as chair of the American Heart Association Quality Oversight Committee, NCDR-ACTION Registry Steering Committee, and VA CART Research and Publications Committee; has served on data monitoring committees for Baim Institute for Clinical Research (formerly Harvard Clinical Research Institute, for the PORTICO trial, funded by St. Jude Medical, now Abbott), Cleveland Clinic, Duke Clinical Research Institute, Mayo Clinic, Mount Sinai School of Medicine, and Population Health Research Institute; has received honoraria from the American College of Cardiology (senior associate editor, Clinical Trials and News, ACC.org; vice-chair, ACC Accreditation Committee), Baim Institute for Clinical Research (formerly Harvard Clinical Research Institute; RE-DUAL PCI clinical trial steering committee funded by Boehringer Ingelheim), Belvoir Publications (Editor-in-Chief, Harvard Heart Letter), Duke Clinical Research Institute (clinical trial steering committees), HMP Global (Editor-in-Chief, Journal of Invasive Cardiology), Journal of the American College of Cardiology (guest editor; associate editor), Population Health Research Institute (for the COMPASS operations committee, publications committee, steering committee, and USA national coleader, funded by Bayer), Slack Publications (chief medical editor, Cardiology Today’s Intervention), Society of Cardiovascular Patient Care (secretary/treasurer), and WebMD (CME steering committees); has served as deputy editor of Clinical Cardiology; has received research funding from Abbott, Amarin, Amgen, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Chiesi, Eisai, Ethicon, Forest Laboratories, Idorsia, Ironwood, Ischemix, Lilly, Medtronic, PhaseBio, Pfizer, Regeneron, Roche, Sanofi, Synaptic, and The Medicines Company; has received royalties from Elsevier (editor, Cardiovascular Intervention: A Companion to Braunwald’s Heart Disease); has served as site co-investigator for Biotronik, Boston Scientific, St. Jude Medical (now Abbott), and Svelte; has served as a trustee of the American College of Cardiology; and has performed unfunded research for FlowCo, Merck, PLx Pharma, and Takeda. Dr. Blankstein has served on the advisory board of Amgen; and has received research support from Amgen, Sanofi, and Gilead Sciences. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2018 American College of Cardiology Foundation