From Intracoronary Physiology to Endotype-Based Treatment: Quality of Life Improvement for INOCA Patients

Background/Objectives: Ischemia with non-obstructive coronary arteries (INOCA) remains an underdiagnosed and undertreated condition due to the extensive diagnostic testing required and heterogeneous pathophysiology of different endotypes, each of which require tailored treatment. This study aimed to explore the effect of intracoronary physiology testing-based endotype-specific medical therapy on quality of life in patients with INOCA. Methods: Intracoronary physiology testing was performed in patients presenting with cardiac symptoms, evidence of significant ischemia on non-invasive testing, and non-obstructive epicardial coronary arteries. Microvascular angina (MVA) was defined as coronary flow reserve ≤ 2.5 and an index of microvascular resistance ≥ 25. Vasospastic angina (VSA) was defined as a >90% vasoconstriction of an epicardial artery during acetylcholine provocation test in the presence of ischemic electrocardiogram changes and chest pain. Quality of life was evaluated using the Seattle Angina Questionnaire 7 (SAQ-7) before the start of new treatment and at the three months follow-up. Results: The total study population consisted of 35 patients (80% women), of whom MVA was observed in 19 (54.3%), VSA in 9 (25.7%), and the combination of MVA and VSA in 3 (8.6%) cases. Four patients (11.4%) had no pathology on intracoronary physiology testing detected. High rates of dyslipidemia (100%), arterial hypertension (85.7%), diabetes (17.1%), and depression and anxiety (34.3%) were documented. In the isolated MVA and VSA groups, adjustment of medical therapy resulted in an improvement in the SAQ-7 summary score at 3 months (p < 0.001 and p = 0.007, respectively). There was no change of SAQ-7 summary score in the mixed endotype group (p = 0.11). Conclusions: Adjustment of medical therapy according to intracoronary physiology testing-based phenotype resulted in improved quality of life as assessed by the SAQ-7. Our findings highlight the importance of invasive testing in patients with clinically suspected INOCA.