Recreational drug users are three times more likely to experience repeated cardiovascular events

New research presented at this year's ESC Congress 2024 in London, UK (30 August – 2 September) shows that patients admitted to the cardiac intensive care unit (ICCU) who have a recent history of recreational drug use are three times more likely to experience another major cardiovascular event within a year than patients without this history.

In patients admitted to the cardiac intensive care unit (ICCU), systematic screening for recreational drugs showed that 11% of patients had recent use. Recreational drug use was associated with a three-fold higher risk of a recurrent major cardiovascular event within 1 year.”

Dr. Raphael Mirailles, study author, Lariboisiere Hospital, Paris, France

Previous work by the same group showed that this recent recreational drug use was associated with a higher rate of hospitalization. However, the long-term cardiovascular consequences of recreational drug use remain unclear.

The aim of this study was to evaluate the prognostic impact of recreational drug use at one-year follow-up to predict major cardiovascular events (including death) in consecutive patients admitted to intensive care units due to acute cardiovascular events from the Addiction in Intensive Cardiac Care Units (ADDICT-ICCU) study.

All consecutive patients admitted to intensive care units in 39 centers across France over two weeks in April 2021 were included. Screening for recreational drug use was performed by systematic urine testing. All patients gave their written informed consent to participate, thereby agreeing to urine testing. One-year follow-up consisted of a clinic visit or direct contact with the patient and the referring cardiologist. The primary composite outcome was the occurrence of a major cardiac event—cardiovascular death, nonfatal myocardial infarction (MI), or stroke. A subgroup analysis was performed in patients who were initially hospitalized for acute coronary syndrome (nonfatal myocardial infarction/angina lasting more than 20 minutes).

Of the 1499 patients examined, 1392 (93%) (mean age 63 years, 70% male) were fully followed up for one year. Among them, 157 (11%) had a first positive test for recreational drug use (cannabis, opioids, cocaine, amphetamines, 3,4-methylenedioxymethamphetamine). [MDMA]). Among these positive results, the following drugs were found: Cannabis: n=136, 9.8%; Heroin and other opioids: n=32, 2.3%; Cocaine: n=23, 1.7%; Amphetamines: n=9, 0.6% MDMA (active ingredient of ecstasy: n=9, 0.6%). More than a quarter of the patients (n=45, 28.7%) tested positive for two or more of these drugs.

The test used for each drug only gave a positive or negative result, but the amount required for a positive test result was significant. The urine drug test used is still positive 2 to 6 days after consumption of the substance, indicating recent exposure rather than regular use. On the other hand, an increase in serious side effects after one year could indicate chronic use.

After one year of follow-up, 94 (7%) patients experienced a major cardiovascular event (including death). Patients who tested positive had a higher rate of major cardiovascular events than non-users (13% versus 6%, a statistically significant finding). Data were then adjusted for several factors – including age, sex, diabetes, current smoking status, cardiovascular disease prior to hospital admission, known chronic kidney disease, history of cancer, principal diagnosis at admission, systolic blood pressure, and heart rate. After this adjustment, recreational drug use was independently associated with a three-fold higher risk of major cardiovascular events.

In the subgroup analysis of 713 patients hospitalized at baseline for acute coronary syndrome, 96 (14%) had a positive drug screen and 50 (7%) experienced major cardiovascular events. In computer modeling of this population, recreational drug use was still independently associated with a three-fold higher risk of major cardiovascular events after accounting for traditional prognostic factors.

Among the 1392 patients examined, there were 64 (4.6%) deaths from cardiovascular disease, 55 (4.5%) among non-users and 9 (5.7%) among recreational drug users. Regarding heart attacks, there were a total of 24 (1.7%) non-fatal heart attacks, 16 (1.3%) among non-users and 8 (5.1%) among drug users. Regarding strokes, there were 10 (0.7%) strokes, 7 (0.6%) among non-users and 3 (1.9%) among drug users.

Among the recreational drugs tested, MDMA (4.1-fold increased risk), heroin and other opioids (3.6-fold), and cannabis (1.8-fold) were significantly associated with major cardiovascular events. There was no statistically significant association with major cardiovascular events for the other drug types.

Dr Mirailles said: “In a large cohort of consecutive patients admitted to cardiac intensive care units for acute cardiovascular events, the prevalence of recreational drug use was 11%. Recreational drug use was associated with a tripling of the risk of a recurrent major cardiovascular event within one year.”

He added: “There is increasing evidence of the worst prognosis associated with recreational drug use, not only in cardiac ICUs but also in conventional ICUs. Despite the high under-reporting rate of recreational drug use, systematic screening is not recommended in current guidelines. It could improve risk stratification of patients and personalized care to promote drug withdrawal. Therefore, systemic screening in intensive care should be considered.”