Correlation between coronary microvascular function and angina status in patients with stable microvascular angina

Abstract

Background: Classical anti-ischemic drugs are the first-line form of treatment in patients with microvascular angina (MVA), but they often fail to achieve a satisfactory control of angina symptoms. It is unknown whether there is any relation between improvement of angina status and changes in microvascular function induced by classical anti-ischemic drugs in MVA patients.

Aim: To assess whether, in MVA patients, the effects of classical anti-ischemic drugs on symptoms and quality of life (QoL) are related to changes in coronary microvascular function.

Patients and methods: We studied 51 patients (59±10 years; 15 men) with MVA. Coronary blood flow (CBF) response to adenosine (ADO) and to cold pressor test (CPT), Seattle Angina Questionnaire (SAQ) and EuroQoL scale were assessed at baseline, in pharmacological washout, and after 12 months under anti-ischemic therapy. Patients were divided into 2 groups: (1) Group 1 included patients with no improvement of QoL (EuroQoL score change < 10 points); (2) Group 2 included patients with QoL improvement (increase in EuroQoL score ≥ 10 points).

Results: At baseline, the 2 groups were similar in age, gender, cardiovascular risk factors, CBF response to ADO and to CPT, SAQ and EuroQoL scores. At follow-up the 2 groups differed only for beta blockers use (27% vs. 88% in group 1 and 2, respectively; p < 0.001). A significant improvement in SAQ score was observed only in group 2. CBF response to both ADO and CPT showed a similar improvement in the 2 groups. No relation was found between changes in coronary microvascular function and in angina status.

Conclusions: In MVA patients beta-blockers are more effective than other anti-ischemic drugs in improving angina symptoms. The improvement of angina status does not seem to be mediated by changes in coronary microvascular function.