Patients presenting with recurrent angina but non-obstructed coronary arteries are increasingly recognized and have a high morbidity and symptomatic burden. These patients are often misdiagnosed and discharged without further investigation or treatment. Current European Society of Cardiology (ESC) guidelines for the management of patients with chronic coronary syndromes recommend beta blockers or calcium channel blockers, depending on the presence of abnormal vasodilatation or abnormal vasoconstriction. Scientific evidence to support this recommendation, however, is scarce and no randomized clinical trial of this differential therapy has been performed in these patients. The aim of the EXAMINE-CAD-DZHK22 trial is therefore to compare for the first time the efficacy of beta blocker (bisoprolol) and calcium channel blocker (diltiazem) therapy in reducing angina symptoms in symptomatic patients with non-obstructed coronary arteries according to coronary physiology testing results. This study is the first to investigate whether coronary physiology testing can guide therapeutic management of these patients depending on whether abnormalities of vasodilatation or vasoconstriction are present. The EXAMINE-CAD-DZHK22 trial will thus fill an important knowledge and evidence gap in the treatment of these highly symptomatic patients, and has the potential to pave the way for future large-scale clinical trials in symptomatic patients with non-obstructed coronary arteries.
EXAMINE-CAD-DZHK22 is a prospective, randomized, double-blind, placebo-controlled, crossover trial investigating the efficacy of beta blocker (bisoprolol) and calcium channel blocker (diltiazem) therapy in symptomatic patients with non-obstructed coronary arteries according to coronary physiological testing results.