Autopsy revised cause of death for nearly half, with many hidden overdoses.
Many reported sudden cardiac deaths (SCDs) can be attributed to non-sudden causes, with drug overdose and even other organ failures in the top five, according to a study probing the discrepancies between autopsy and SCD surveillance records reported to the medical examiner.
About 40% of such deaths reported from San Francisco County between February 1, 2011 and March 1, 2014 were not unforeseen and were noncardiac, and half were not even arrhythmic, according to a prospective autopsy analysis published in the June 19 issue of Circulation.
Only 55.8% turned out to be autopsy-defined sudden arrhythmic deaths, Zian Tseng, MD, MAS, a cardiac electrophysiologist at the University of California San Francisco, and colleagues reported.
"[T]hese data reflect the decreasing prevalence of coronary disease and increasing prevalence of nonischemic causes; therefore, further inroads into reducing the overall burden of sudden deathrequires investigation and earlier recognition of nonischemic and nonarrhythmic causes," they wrote.
"We can't assume that all sudden deaths are cardiac," Tseng said in an interview. "I think it's a wake up call for cardiologists overall to say that we can say that death is sudden, but we can't say that it's SCD."
The study's main findings applied to urban and suburban communities alike. On subgroup analysis, the leading causes of death were found to be coronary disease (32%), occult overdose (13.5%), cardiomyopathy (10%), cardiac hypertrophy (8%), and neurological causes (5.5%).