Presence and extent of coronary calcified plaque evaluated by coronary computed tomographic angiography are independent predictors of ischemic stroke in patients with suspected coronary artery disease.

Although ischemic stroke and coronary artery disease (CAD) share common risk factors and pathophysiology, the risk of stroke in patients with CAD remains unclear. We sought to evaluate the risk of ischemic stroke in patients with suspected CAD according to coronary computed tomographic angiography (CCTA) and single-photon emission computed tomography (SPECT) findings. Presence, severity, and extent of CAD were evaluated in 1137 patients with suspected CAD who underwent CCTA and SPECT. Primary outcome was the occurrence of ischemic stroke. During follow-up (median 26 months), ischemic stroke was observed in 25 patients (2.2%). The presence of coronary plaque on CCTA was associated with the occurrence of ischemic stroke (2.8 vs. 0.6%; p = 0.029), while the presence of PD on SPECT was not (2.0 vs. 2.3%; p = 0.768). Stroke occurrence was not increased by the presence of significant stenosis of ≥50% DS (2.8%; p = 0.943), but was further increased by the plaque presence in ≥2 vessels (6.1 %; p = 0.001) or ≥3 segments (4.1%; p = 0.019). Presence of calcified plaque, and calcified plaque in ≥2 segments were also associated with ischemic stroke occurrence (4.3%; p < 0.001, and 5.6%; p < 0.001, respectively) and were the independent risk factors when adjusted to age of ≥65, hypertension, presence of any coronary plaque and plaque in ≥3 segments (adjusted HR 6.09; 95% CI 1.38-26.87; p = 0.017, and adjusted HR 5.47; 95% CI 1.85-16.19; p = 0.002, respectively). The risk of ischemic stroke was associated with the presence and extent of coronary atherosclerotic plaque evaluated by CCTA, but not with the presence and extent of myocardial ischemia evaluated by SPECT. Especially, calcified coronary plaque presence and extent were the independent predictors of ischemic stroke and allowed further risk stratification.