Coronary microvascular dysfunction is an independent predictor of developing cancer in patients with non-obstructive coronary artery disease

Aims Cardiovascular disease and cancer share common pathogenesis and risk factors. Coronary microvascular dysfunction (CMD), reflecting impaired coronary microvascular dilation in response to stress, is related to a higher risk of major cardiovascular events; however, its association with cancer has not been explored. Methods A retrospective study on 1042 patients with non-obstructive coronary artery diseases (NOCADs) was performed. Data and results regarding demographic, clinical history, diagnostic coronary reactivity test, and cancer occurrence were collected. Coronary microvascular dysfunction was defined as coronary flow reserve (the ratio of hyperaemic blood flow to resting blood flow) ≤2.5. Thirty-four per cent had CMD (67.4% female and the average age was 52.4 ± 12.2 years). Of 917 patients with no history of cancer, 15.5% developed cancer during follow-up [median of 9 (4, 16) years]. Kaplan–Meier analysis showed that CMD patients had lower cancer-free survival compared with those without CMD (log-rank P = 0.005). Cox proportional hazard analyses showed that after adjusting for age, sex, hypertension, diabetes, smoking, and glomerular filtration rate, CMD is independently associated with cancer [hazard ratio, 1.4; 95% confidence interval (CI), 1.09–2.04; P = 0.04]. The rate of major adverse cardiovascular events (MACE) was significantly higher in CMD patients compared with that in non-CMD patients who had a previous history of cancer [odds ratio (OR), 2.5; 95% CI, 1–6.2; P = 0.04] and those with no history of cancer (OR, 1.4; 95% CI, 1.01–1.9; P = 0.044). Conclusion Coronary microvascular dysfunction is associated with cancer incidence in patients presenting with NOCADs. This study emphasizes follow-up in patients with CMD to evaluate the risk of MACE as well as potential malignant diseases.