Abstract
CORRESPONDENCE TO: Cunzhi Lu, MD. Department of Nuclear Medicine, Xuzhou Central Hospital, No. 199, Jiefangnan Road, Xuzhou 221009, China. Email: 13912045900@163.com; Yuetao Wang, MD. Department of Nuclear Medicine, The Third Affiliated Hospital of Soochow University, No. 185, Juqian Street, Changzhou 213003, China; Institute of Clinical Translation of Nuclear Medicine and Molecular Imaging, Soochow University, Changzhou, China. Email: yuetao-w@163.com. BACKGROUND: Ischemia with nonobstructive coronary arteries (INOCA) is prevalent among patients with angina, is linked to major adverse cardiovascular events (MACEs), and is often driven by endothelial dysfunction. This study aimed to assess the efficacy of the cold pressor test (CPT) in identifying individuals at elevated risk for MACEs among patients with INOCA. METHODS: A total of 124 INOCA inpatients were included in the retrospective cohort study. Clinical data including age, gender, BMI, hypertension, hyperlipidemia, diabetes mellitus (DM), active smoking, and symptoms were collected from medical records. A positive CPT-myocardial perfusion imaging (MPI) result was considered to be the presence of a reversible perfusion defect with a summed difference score (SDS) ≥2. The patients were routinely followed-up according to standard protocol. An MACE was defined as a composite endpoint including all-cause mortality, late coronary revascularization [≥3 months following single-photon emission computed tomography (SPECT)-MPI], nonfatal myocardial infarction, rehospitalization due to angina, heart failure, and stroke. RESULTS: The number of positive CPT-MPI cases was 49 (39.5%) and that of negative CPT-MPI cases was 75 (60.5%). Compared with negative CPT-MPI, positive CPT-MPI group had a higher percentage of DM [16 (32.7%) vs. 13 (17.3%)], coronary atherosclerosis [33 (67.3%) vs. 32 (42.7%)], and ST-T segment changes on routine admission electrocardiogram (ECG) [37 (75.5%) vs. 42 (56.0%)] (all P values <0.05). Univariate and multivariate logistic regression analyses indicated coronary atherosclerosis as independent risk factor for positive CPT-MPI [odds ratio (OR) 2.68, 95% confidence interval (CI): 1.22-5.90; P=0.014]. The proportion of positive CPT-MPI was higher in patients with MACEs than in patients without them [6 (32.7%) vs. 16 (8%); P <0.05]. In the multivariate Cox proportional hazards model, only positive CPT-MPI (hazard ratio 2.97, 95% CI: 1.02-8.58; P=0.04) was significantly associated with MACE occurrence. CONCLUSIONS: Among patients with INOCA <39.5% had positive CPT, which was significantly related to MACE occurrence. In patients with positive CPT, the risk of MACE increased twofold. Coronary atherosclerosis was the independent risk factor of positive CPT. CPT-MPI offers valuable insights for risk stratification and treatment decision-making in patients with INOCA, particularly in identifying those at higher risk of adverse cardiovascular events.