Cocaine Use Linked to Higher Mortality Following SAH

Caroline Cassels

April 08, 2013

San Diego, California — Acute cocaine use in patients with aneurysmal subarachnoid hemorrhage (aSAH) is associated with higher in-hospital death, as well as a significantly increased risk for aneurysm rerupture, new research shows.

A retrospective study showed nearly a 3-fold increased risk for hospital mortality among acute cocaine users with aSAH compared with their counterparts who did not use cocaine 72 hours before their event.

"We found that recent cocaine use was an independent predictor of in-hospital mortality in patients with aSAH and that this significant association was observed despite any difference in the severity of patients' initial presentation," said study investigator Tiffany Chang, MD, Johns Hopkins University Hospital in Baltimore, Maryland.

Dr. Chang added that although acute cocaine use was also linked to higher rates of aneurysm rerupture, this did not entirely explain the mortality difference between users and nonusers.

The findings were presented here at the American Academy of Neurology (AAN) 65th Annual Meeting.

Cocaine Use in aSAH Common

It is estimated that aSAH accounts for approximately 5% of all strokes and has an annual incidence of about 30% in the United States, said Dr. Chang. She added that recent cocaine use, defined as use within 72 hours before aSAH, is reported in up to 33% of cases.

She also noted that although acute cocaine use has been temporally associated with aSAH, there have been varying reports describing how it affects patient presentation, complications, and outcomes.

To examine the effect of acute cocaine use on presentation and outcomes following aSAH, the researchers reviewed prospectively collected data on all patients with aSAH admitted to John Hopkins Medical Institutions between 1991 and 2009.

Excluded from the study were patients with aSAH due to other causes, such as trauma, vascular malformation, tumors, or venous bleeding.

Patients with recent cocaine use were identified through positive urine toxicology results or a self-reported history of cocaine use in the past 72 hours.

These patients were then compared with aSAH patients without recent cocaine exposure. Study outcomes included in-hospital mortality, functional status at discharge and first clinic appointment after discharge, delayed cerebral ischemia (DCI), and aneurysm rerupture.

The investigators also evaluated other factors that could affect outcomes, including age, admission Glasgow Coma Scale (GCS) Hunt and Hess grade, World Federation of Neurological Societies scale, cocaine use, intraventricular hemorrhage (IVH), and hydrocephalus.

Higher Rate of Rerupture

A total 1134 patients — 142 cocaine users and 992 nonusers — were included in the analysis.

The researchers found no significant differences between the 2 groups with respect to patient characteristics in terms of GCS at admission, poor grade Hunt and Hess score, IVH, or hydrocephalus.

However, cocaine users were significantly younger than nonusers: 49 years (±10.6) vs 53.1 years (±14.3).

Hospital mortality for the entire cohort was 18.3%. However, at 26%, mortality in cocaine users was significantly higher than the 17% in non–cocaine users (P = .010). After multivariate analysis this remained statistically significant with adjusted odds of hospital mortality 2.9-fold higher among cocaine users (95% confidence interval, 1.761 - 4.630; P < .001).

The investigators also found that cocaine users had a higher rate of rerupture compared with nonusers: 7.7% vs 2.7% (P = .002), respectively.

But after investigators excluded patients with aneurysm rerupture from both groups, hospital mortality remained elevated in patients with cocaine use compared with those without: 25% vs 16% (P = .019). This finding suggests, said Dr. Chang, that aneurysm rerupture was not wholly responsible for the higher mortality rate among cocaine users.

Age a Factor in Outcome?

Interestingly, the researchers found no difference in functional outcomes among cocaine users vs nonusers at discharge or at first postdischarge visit, a finding that may be explained by the age difference between the 2 study groups.

"One of the potential driving factors here could be that the cocaine group was significantly younger than the noncocaine group, and perhaps younger patients are more likely to have better functional recovery following subarachnoid hemorrhage," said Dr. Chang.

The researchers found that cocaine users were more likely to have DCI. However, this association was not significant after adjustment for other confounding factors. The analysis also revealed no difference in rates of IVH between the 2 groups.

Although the study had several limitations (most notably its retrospective nature), these findings suggest that patients with aSAH and acute cocaine use may warrant closer investigation.

Further, Dr. Chang said, the mechanisms for the nearly 3-fold increased odds of death associated with cocaine use warrants further investigation.

Commenting on the findings for Medscape Medical News, Marc Lazzaro, MD, assistant professor of neurology and neurosurgery, Medical College of Wisconsin in Milwaukee, and a member of the AAN, said aSAH in patients using cocaine has been previously reported with mixed implications regarding outcomes. He said he found it interesting that cocaine use was not independently associated with vasospasm-related infarcts in this cohort.

He added that the 3-fold increase in mortality among cocaine users found in this study could have a considerable effect on patient management and warrants further investigation.

Dr. Chang and Dr. Lazzaro have disclosed no relevant financial relationships.

American Academy of Neurology (AAN) 65th Annual Meeting. Abstract S12. Presented March 19, 2013.