What are appropriate clinical endpoints? From device failure assessment to angina evaluation

Angina pectoris is chest pain caused by ischemia of the myocardium secondary to a supply/demand mismatch. Myocardial ischemia is caused by one or more flow-limiting stenoses in one or more of the epicardial coronary arteries, while in a minority it is caused by coronary vasospasms or microvascular dysfunction. Historically, clinical research evaluating percutaneous coronary intervention (PCI) treatment is mostly focused on the quantification of the failure of the treatment including (cardiac) death, myocardial infarctions (MIs), repeat revascularizations, and stent thrombosis (ST). A patient-reported outcome (PRO) instrument quantifies the status of a patient's health condition in which the information comes directly from the patient. The most widely used PRO to assess angina is the Seattle Angina Questionnaire (SAQ). The SAQ has five domains, including "physical limitation", "angina stability", "angina frequency", "treatment satisfaction", and "disease perception". Angina can be assessed using PRO or site-reported outcomes, both with their own strengths and weaknesses.