Background

Background: Increased prevalence of right and left ventricular dysfunction in patients with chronic obstructive lung disease (COPD) has been controversial and understudied. The study by Vizza et al ₁ showed decreased RVEF but not LVEF in patients with severe pulmonary disease. Their study lacked a control group and most of their patients had severe lung disease. In contrary, LVEF was found to be decreased in an experimental animal study in dogs with COPD ₂ and in a small study of patients with COPD.₃ Furthermore, RVEF was found to be normal in patients with COPD at rest by other investigators.₄,₅ The goal of this study was to evaluate any association between COPD and on right ventricular cardiac function. We used RVEF as a measure of right ventricular function in patients with the diagnosis of COPD and a control group with diagnosis other than COPD.

Methods

This study is a cross-sectional study of a series of 157 patients, who underwent LVEF assessment using blood pooled scintigraphy (MUGA) for clinical indications by their physicians. These patients underwent simultaneous measurement of RVEF for this study. Patients with a history of smoking or COPD were compared to a control group using Chi square and Fisher Exact Test. The diagnosis of COPD was extracted from the patient's past medical history. The severity of COPD was not recorded in this study.

LVEF and RVEF were categorized as normal (EF > 50%) or decreased (mild: EF < 50%, moderate: EF< 40% and severe: EF < 30%). Using univariate analysis, we compared mean LVEF and RVEF in patients with or without a history of COPD.

MUGA Technique

Processing

Discussion

Our study evaluated the occurrence of low LVEF and RVEF in patients with COPD. We found no differences in the prevalence of low RVEF in patients with or without COPD. Our study is consistent with smaller trials showing normal resting RVEF when considering all comers. ₄,₅,₆ Most of the studies with documented depressed RVEF have been found in patients with severe pulmonary hypertension ₁,₃,₅,₇, severe resting COPD,₃,₈ right heart failure or after exercise. ₆ Burghuber et al. found that the assessment of RVEF is a poor indicator of overall right ventricular function in patients with COPD.₉ The finding of normal LVEF in COPD patients in our study is consistent with most trial that COPD does not directly effect LVEF unless pulmonary hypertension or coronary artery disease is present.₃,_{8 10} The lack of negative effect of COPD in our study as an independent factor on EF needs to be confirmed in a larger population.

Conclusion

We found that patients with a history of COPD do not have lower RVEF in comparison to other patients. This suggests that COPD patients without evidence of right heart failure or pulmonary hypertension might not be at risk for low right ventricular EF. However, due to small size, our study needs to be confirmed in a larger population.

Limitation

Men were the predominant gender in our study limiting our results to men. This study was a cross-sectional study and the number of patients with COPD was small limiting our results. Furthermore, we did not have any data about the severity of COPD.

Figure 1

Table 1: LVEF and RVEF prevalence in patients with and without COPD (chronic obstructive pulmonary disease)

Correspondence to

M. Reza Movahed, MD, PhD, FACP, FACC, FSCAI, FCCP Associate Professor Director of Coronary Care Unit University of Arizona Sarver Heart Center Department of Medicine, Division of Cardiology 1501 North Campbell Ave. Tucson, AZ, 85724 Tel: (520)-626-2000 (949)-400-0091 E mails: rmovahed@email.arizona.edu rmova@aol.com