Kounis syndrome shows male predominance 75 percent and 4 percent mortality in systematic review

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The American journal of cardiology Published June 1, 2026 Medically reviewed June 1, 2026 Study authors: Kalambay Junior David, Tashli Mohammad, Zaman Mohammad, Elwidaa Ahmed, Shet Vinay, Phillip Madonna PubMed ↗ DOI ↗ By Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

Key Takeaway

Note that Kounis syndrome evidence is limited to case reports, with male predominance 75 percent and mortality 4 percent.

This is a systematic review and meta-analysis of 71 extractable cases of Kounis syndrome, a condition involving allergic or hypersensitivity reactions triggering coronary events. The review synthesized data on demographic patterns, clinical features, management strategies, and outcomes, including ST-segment elevation, angiographic abnormalities, subtype distribution, mortality, shock, and cardiac arrest.

The authors report a pooled male predominance of 75 percent. Angiographic abnormalities were present in 42 percent of cases. Recovery was the predominant outcome, and mortality was low at 4 percent.

Key limitations noted by the authors include that the available evidence is largely limited to case reports and small case series, reporting variability limits definitive inference, and there is substantial heterogeneity for Type I KS. The authors caution against overstating associations between severity markers and mortality, trigger-specific demographic patterns, consistent male predominance, and generally favorable outcomes.

Practice relevance was not reported. The findings suggest a generally favorable prognosis but are based on low-certainty evidence, and clinical application should be cautious.

Study Details

Study typeMeta analysis

EvidenceLevel 1

PublishedJun 2026

PMID41833647

View Original Abstract ↓

Kounis syndrome (KS), an allergic acute coronary syndrome, remains incompletely characterized because available evidence is largely limited to case reports and small case series. We conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review and meta-analysis with pooled patient-level data to quantitatively synthesize demographic patterns, clinical features, management strategies, and outcomes across published KS cases. A PubMed search identified 892 records, of which 3 studies met eligibility criteria, yielding 71 extractable cases. Study-level proportions were pooled using random-effects models with assessment of between-study heterogeneity. Age distribution varied by trigger, with contrast-related cases occurring at older ages, cephalosporin-associated cases at intermediate ages, and nonsteroidal anti-inflammatory drug-related cases at younger ages. Male predominance was consistent, with pooled estimates approximating 75%. ST-segment elevation was common, and angiographic abnormalities were present in 42%. Subtype distribution demonstrated substantial heterogeneity, particularly for Type I KS. Allergic-directed therapies, including corticosteroids and antihistamines, were frequently reported, whereas ischemia-directed therapies and invasive procedures were inconsistently documented. Recovery was the predominant outcome (94%), while mortality was low (4%). Shock and cardiac arrest occurred in a minority of cases, and pooled estimates demonstrated only a weak association between severity markers and mortality. In conclusion, this systematic review and meta-analysis provide a quantitative synthesis of KS, demonstrating trigger-specific demographic patterns, consistent male predominance, and generally favorable outcomes, although reporting variability limits definitive inference.