Co-morbidity contributes to predict mortality of patients with chronic obstructive pulmonary disease

Abstract

The aim of this study was to assess the prognostic role of co-morbidity in severe chronic obstructive pulmonary disease (COPD). A cohort of 270 COPD patients, mean (+/-SD) age 67+/-9 yrs, consecutively discharged from a University Hospital after an acute exacerbation was studied. Mean (+/-SD) forced expiratory volume in one second (FEV1) was 34+/-16% of predicted and FEV1/forced vital capacity (FVC) was 40.5+/-13.8%. The most common co-morbid diseases were: hypertension (28%), diabetes mellitus (14%), and ischaemic heart disease (10%). Clinical, electrocardiogram (ECG), and respiratory function data taken at the time of discharge were collected from the clinical records. The Charlson's index was used to quantify co-morbidity. Follow-up was conducted by means of telephone calls. Multivariate survival analysis was used to identify the independent predictors of death. The median survival of the cohort was 3.1 yrs. Death was predicted by the following variables: age (hazard rate (HR) 1.04; 95% confidence intervals (95% CI) 1.02-1.05), ECG signs of right ventricular hypertrophy (HR 1.76; 95% CI 1.30-2.38), chronic renal failure (HR 1.79; 95% CI 1.05-3.02), ECG signs of myocardial infarction or ischaemia (HR 1.42; 95% CI 1.02-1.96), FEV1 < 590 mL (HR 1.49; 95% CI 0.97-2.27). A score based upon these variables predicted mortality at 5 yrs with a sensitivity of 63% and a specificity of 77%. Selected co-morbid diseases and electrocardiogram signs of right ventricular hypertrophy play a major prognostic role in advanced chronic obstructive pulmonary disease. The clinical assessment of patients with chronic obstructive pulmonary disease should include these important and easily measurable variables.

Sex differences in mortality in patients with COPD

“…Surprisingly, when respiratory mortality was compared by BODE quartiles, a higher mortality was found in males than in females only in the most severe quartile. This is an important finding that reproduces those reported by CELLI et al [22] and INCALZI et al [35], which suggests that the course of COPD per se, may be similar in females and males as the COPD progresses and that the differences in overall survival in males with more severe COPD could possibly be due to added comorbidity. This could also explain the differences in all-cause mortality between both sexes.…”

“…Although the impact of comorbidities in the clinical course of COPD was described almost 10 yrs ago [35], it is only now that it has begun to receive specific attention [36]. In the present study, comorbidities seemed to impact only in all-cause mortality in males (tables 4 and 5).…”

Epidemiology of chronic obstructive pulmonary disease

“…Follow-up of a series of cases with well advanced COPD have shown that in addition to respiratory parameters like oxygen tension in arterial blood (Pa,O 2 ), carbon dioxide tension in arterial blood (Pa,CO 2 ), FEV1, FVC and cor pulmonale, other markers of the cardiovascular function like ventricular ejection fraction and ECG abnormalities are also associated to increased mortality [43][44][45]. Little is known about the specific causes of death in subjects with COPD.…”

COPD and PE: A clinical dilemma

“…A careful evaluation of the epidemiology of both diseases fi nds the prevalence of PE in COPD similar to that of other disease population groups, and increased combined morbidity and mortality is similar to that of COPD and heart failure, or COPD and myocardial infarction (Incalzi et al 1997;Groenewegan et al 2003;Lee et al 2003;Holguin et al 2005;Huiart et al 2005;Sin et al 2006). Lesser and Hartmann's work confi rmed that PE does not appear to favor COPD (Lesser et al 1992;Hartmann et al 2000).…”