Association between preoperative platelet count and perioperative cardiovascular events after noncardiac surgery

Platelets are major players in the pathogenesis of cardiovascular events, and the number of circulating platelets in whole blood is routinely available in clinical testing. The relationship between the preoperative platelet count and major adverse cardiovascular events (MACE) after noncardiac surgery is uncertain.

In this paper we aim to explore the relationship between abnormal platelet counts and major adverse cardiac events (MACE) after noncardiac surgery.

We identified adults aged ≥18 years undergoing noncardiac surgery from 2009 to 2015 from the National Surgical Quality Improvement Program. Preoperative platelet counts within 90 days of surgery were recorded. Patients were prospectively followed for 30 days. The primary outcome was 30-day MACE (a composite of death, myocardial infarction, or stroke). Multivariable logistic regression models estimated the association between platelet count and the odds of postoperative outcomes.

Among 3 053 308 surgical patients, 7.5% had thrombocytopenia (6% mild [platelet count 100-150 × 10⁹/L] and 1.5% moderate-severe [<100 × 10⁹/L]), and 4.4% had thrombocytosis (4% moderate [400-600 × 10⁹/L] and 0.4% severe [>600 × 10⁹/L]). There was a U-shaped relationship between platelet count and MACE. The adjusted odds of MACE were elevated in mild (adjusted odds ratio [aOR], 1.44; 95% CI, 1.39-1.48) and moderate-severe thrombocytopenia (aOR, 2.79; 95% CI, 2.69-2.90) and in moderate (aOR, 1.57; 95% CI, 1.52-1.63) and severe (aOR, 1.91; 95% CI, 1.74-2.09) thrombocytosis. Findings were consistent for the individual endpoints of death, myocardial infarction, and stroke.

In adults undergoing noncardiac surgery, preoperative thrombocytopenia and thrombocytosis were identified in nearly 12% of cases and were associated with increased odds of cardiovascular events at 30 days.