Decreases in symptom load and improvements in quality of life are important goals in the invasive treatment of symptomatic chronic coronary syndrome (CCS). To date, it is not known which patients profit most from the invasive treatment. This sub-analysis of the prospective, multi-centre PLA-pCi-EBO trial includes 145 patients with symptomatic CCS and successful PCI. The prespecified endpoints angina pectoris and quality of life (Seattle Angina Questionnaire-SAQ) were assessed 1 and 6months after PCI. Predictors of symptom improvement were analyzed by logistic regression analysis. Quality of life, physical limitation, and angina frequency markedly improved 6months after PCI. Worse baseline health status (i.e., low SAQ subscales) was the best predictor of highly clinically relevant improvements (≥ 20 points in SAQ subscales) in symptom load and quality of life. Demographic factors (age, sex, body-mass index) and cardiovascular disease severity (number of involved vessels, ejection fraction) did not predict relevant improvements after PCI. The influence of psychologic traits has not previously been assessed. We found that neither optimism nor pessimism had a relevant effect on symptomatic outcome. However, patients who exercised more after PCI had a much larger improvement in quality of life despite no differences in physical limitation or angina frequency. PCI effectively reduces symptom load and improves quality of life in patients with symptomatic CCS. Reduced baseline health status (symptom load, quality of life) are the only relevant predictors for improvements after PCI. Physical activity after PCI is associated with greater benefits for quality of life. The German Clinical Trials Register registration number is DRKS0001752.