Electrocardiographic signs of chronic cor pulmonale - A negative prognostic finding in chronic obstructive pulmonary disease

Background-Chronic cor pulmonale (CCP) is a strong predictor of death in ch ronic obstructive pulmonary disease (COPD)I The aims of this study were to assess the prognostic role of individual ECG signs of CCP and of the intera ction between these signs and abnormal arterial blood gases. Methods and Results-Two hundred sixty-three patients (217 men) with COPD, m ean age 67+/-9 years, were grouped according to whether they had no ECG sig ns (group 1, n=100) or greater than or equal to 1 ECG signs (group 2, n = 1 63) of CCP and were followed up for 13 years after an exacerbation of respi ratory failure, The median survival was significantly shorter in group 2 th an in group 1 (2.58 versus 3.45 years, respectively; Mantel-Cox test, 9.58; P=0.002). The Cox regression analysis identified S1S2S3 pattern, right atr ial overload (RAO), and alveolar-arterial oxygen gradient (PAO(2)-PaO2) >48 mm Hg during oxygen therapy as the strongest predictors of death, with haz ard rate (HR)=1.81 (95% CI, 1.22 to 2.69), HR=1.58 (95% CI, 1.15 to 2.18), and HR=1.96 (95% CI, 1.19 to 3.25), respectively, The median survivals of p atients having both S1S2S3 pattern and RAO (n=14) and of patients having ei ther S1S2S3 pattern or RAO (n=77) were 1.33 and 2.70 years, respectively (P =0.022). Group 2 patients had a 3-year survival of 18% or 53%, depending on whether their PAO(2)-PaO2 during oxygen therapy was or was not >48 mm Hg. Conclusions-Some ECG signs of CCP and PAO(2)-PaO2 >48 mm Hg during oxygen t herapy qualified as a simple and inexpensive tool for targeting subsets of COPD patients with severe or very severe short-term prognosis.