July 07, 2016
2 min read
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Variant angina with aborted sudden cardiac death tied to poor outcomes

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Among patients with variant angina, those with aborted sudden cardiac death have worse outcomes than those without it, researchers reported in the Journal of the American College of Cardiology.

“Our findings supported [implantable cardioverter defibrillators] in these high-risk patients as a secondary prevention because current multiple vasodilator therapy appeared to be less optimal,” the researchers wrote.

Researchers compared the long-term risk for mortality and ventricular tachyarrhythmic events in patients with variant angina with aborted sudden cardiac death (n = 188) compared with patients with variant angina without aborted sudden cardiac death (n = 1,844). A secondary analysis evaluated the difference in cardiac mortality between patients who received ICDs and those who did not in the aborted sudden cardiac death group.

Patients were enrolled at 13 heart centers in South Korea between March 1996 and September 2014. The mean age of patients who experienced aborted sudden cardiac death was 52.8 years; 76% were men. All patients received vasodilators. The primary endpoint was cardiac death and the secondary endpoint was all-cause mortality. Median follow-up was 7.5 years.

Cardiac death higher

According to the researchers, the incidence rate of cardiac death was significantly higher in patients with aborted sudden cardiac death (24.1 per 1,000 patient-years vs. 2.7 per 1,000 patient-years; adjusted HR = 7.26; 95% CI, 4.21-12.5).

For all-cause mortality, the incidence rate was higher for patients with aborted sudden cardiac death (27.5 per 1,000 patient-years vs. 9.6 per 1,000 patient-years; adjusted HR = 3; 95% CI, 1.92-4.67).

When the researchers performed propensity-score matching of 172 patients with aborted sudden cardiac death and 172 without it, those with aborted sudden cardiac death had higher risk for cardiac death (HR = 9.81; 95% CI, 3.02-31.8) and all-cause mortality (HR = 4.09; 95% CI, 2.28-10.5).

The researchers found that predictors of aborted sudden cardiac death were as follows:

age (OR per 1-year increase = 0.98; 95% CI, 0.96-1);

hypertension (OR = 0.51; 95% CI, 0.37-0.7);

hyperlipidemia (OR = 0.38; 95% CI, 0.25-0.58);

family history of sudden cardiac death (OR = 3.67; 95% CI, 1.27-10.6);

multivessel spasm (OR = 2.06; 95% CI, 1.33-3.19); and

left anterior descending artery spasm (OR = 1.4; 95% CI, 1.02-1.92).

In addition, 24 patients with aborted sudden cardiac death received an ICD and more vasodilator treatment. Six of these patients experienced ventricular fibrillation and one patient died of intractable ventricular fibrillation.

“Current multiple vasodilator therapy appeared to be suboptimal,” the researchers wrote. “Therefore, ICD implantation, together with multiple vasodilator therapy, might be necessary as a secondary prevention treatment, although this strategy should be tested in a future large and prospective clinical trial.”

Study underpowered

In an accompanying editorial, Julia H. Indik, MD, PhD, from Sarver Heart Center, University of Arizona, Tucson, wrote that the study was too underpowered to fully answer whether or not an ICD is the solution for these patients.

In addition, Indik wrote, “It is unknown what factors might have biased physicians to implant an ICD; therefore, it remains unproven whether an ICD can lower the risk of death in patients with variant angina resuscitated from [out-of-hospital cardiac arrest]. Nonetheless, the observation of apparent improved survival in ICD patients is compelling and warrants further prospective research.” – by Tracey Romero

Disclosure: The researchers and Indik report no relevant financial disclosures.