Plaque rupture and sudden death related to exertion in men with coronary artery disease.
Level 4 - case-series / case-control
Post-mortem cross-sectional comparative autopsy series
PubMed 10078489 · doi:10.1001/jama.281.10.921
What was done
Researchers conducted an autopsy survey of 141 men with severe coronary artery disease who died suddenly (116 at rest, mean age 51; 25 during strenuous activity or emotional stress, mean age 49) at a medical examiner's office. Coronary arteries were perfusion-fixed and segments with >50% luminal narrowing were examined histologically. Ruptured plaques were defined as intraplaque hemorrhage with fibrous cap disruption and luminal thrombus. Pre-death exertion was classified by death investigators, and risk factors were assessed in multivariate analyses.
What was found
The exertional-death group had more vulnerable plaques per subject than the at-rest group (mean [SD], 1.6 [1.5] vs 0.9 [1.2]; P = .03). Plaque rupture was the culprit lesion in 68% (17/25) of exertional deaths versus 23% (27/116) of rest deaths (P < .001). Intraplaque hemorrhage was present in 72% (18/25) of exertion deaths vs 41% (47/116) of rest deaths (P = .007). Acute myocardial infarction on histology was present in 0 of 25 exertion deaths versus 15 of 116 (13%) rest deaths. Men dying during exertion had a higher total-to-HDL cholesterol ratio (8.2 [3.0] vs 6.2 [2.7]; P = .002), and most (21/25) were unconditioned. On multivariate analysis, both exertion (P = .002) and total-to-HDL cholesterol ratio (P = .002) were independently associated with acute plaque rupture.
Why it matters
This study provides direct pathological evidence that acute plaque rupture and intraplaque hemorrhage, rather than completed myocardial infarction, is the primary underlying mechanism linking strenuous exertion to sudden cardiac death in men with coronary disease.
Limits
The study included only men and relied on post-mortem investigator reports to classify exertion. The exertion group was small (n = 25) and grouped physical activity together with emotional stress. Autopsy series inherently carry selection bias and cannot assess absolute incidence.
Cited by
- contradicts High-intensity interval training is negatively associated with heart attacks, and high intensity makes soft plaque less likely rather than more likely to break off.