['We examined the effect of cardiac comorbidity on mortality and postoperative complications following surgery for primary non-small cell lung cancer.', 'Between October 2001 to December 2005, 1067 consecutive patients underwent lung resection for primary cancer within a single centre; patient data was collected prospectively. Two hundred and seventy-one patients had a history of cardiac comorbidity, which included 196 angina, 118 myocardial infarction, 36 revascularisation, 10 congestive cardiac failure and 19 rhythm disorders (numbers not mutually exclusive). To account for differences in case-mix we used logistic regression to develop a propensity score for cardiac comorbidity group membership and then performed a propensity-matched analysis. Kaplan-Meier curves were used to assess follow-up mortality.', 'Patients with cardiac comorbidity were more likely to be hypertensive, have severe dyspnoea, diabetes, current or ex-smokers and were older. After performing propensity matching to account for these differences we successfully matched 199 patients with cardiac comorbidity to 398 patients with no cardiac history. There was no difference in in-hospital mortality (2.5% vs 3%, p=0.73), myocardial infarction (0.5% vs 0.3%, p>0.99), arrhythmia (15.6% vs 14.1%, p=0.62), renal failure (2% vs 1.5%, p=0.65), stroke (0.5% vs 0.3%, p>0.99), respiratory insufficiency (4% vs 3.3%, p=0.64), reintubation (1% vs 2.5%, p=0.35), tracheostomy (4% vs 7.8%, p=0.08), intensive care readmission (8.5% vs 6.5%, p=0.37) and length of stay (8 days vs 8 days, p=0.98). Three-year survival was similar (61.4% vs 56.2%, p=0.39). No differences in outcomes existed with different cardiac conditions.'] Is cardiac comorbidity a risk factor for mortality and morbidity following surgery for primary non-small cell lung cancer?