Prevalence of cardiac comorbidities, and their underdetection and contribution to exertional symptoms in COPD: results from the COSYCONET cohort

Abstract

Background

A substantial prevalence of cardiovascular disease is known for COPD, but detection of its presence, relationship to functional findings and contribution to symptoms remains challenging. The present analysis focusses on the cardiovascular contribution to COPD symptoms and their relationship to the patients’ diagnostic status, medication and echocardiographic findings.

Methods

Patients from the COPD cohort COSYCONET with data on lung function, including FEV₁, residual volume/total lung capacity (RV/TLC) ratio, diffusing capacity TLCO, and echocardiographic data on left ventricular ejection fraction (LVEF) and end-diastolic diameter (LVEDD), medical history, medication, modified British Medical Research Council dyspnea scale (mMRC) and Saint Georges Respiratory Questionnaire (SGRQ) were analyzed.

Results

A total of 1591 patients (GOLD 0–4: n=230/126/614/498/123) fulfilled the inclusion criteria. Ischemic heart disease, myocardial infarction or heart failure were reported in 289 patients (18.2%); 860 patients (54%) received at least one cardiovascular medication, with more than one in many patients. LVEF<50% or LVEDD>56 mm was found in 204 patients (12.8%), of whom 74 (36.3%) had neither a cardiovascular history nor medication. Among 948 patients (59.6%) without isolated hypertension, there were 21/55 (38.2%) patients with LVEF<50% and 47/88 (53.4%) with LVEDD>56 mm, who lacked both a cardiac diagnosis and medication. LVEDD and LVEF were linked to medical history; LVEDD was dependent on RV/TLC and LVEF on FEV₁. Exertional COPD symptoms were best described by mMRC and the SGRQ activity score. Beyond lung function, an independent link from LVEDD on symptoms was revealed.

Conclusion

A remarkable proportion of patients with suspicious echocardiographic findings were undiagnosed and untreated, implying an increased risk for an unfavorable prognosis. Cardiac size and function were dependent on lung function and only partially linked to cardiovascular history. Although the contribution of LV size to COPD symptoms was small compared to lung function, it was detectable irrespective of all other influencing factors. However, only the mMRC and SGRQ activity component were found to be suitable for this purpose.

Keywords:

• COPD
• heart failure
• echocardiography
• medication
• dyspnea
• symptoms

Acknowledgments

This work was supported by the German Federal Ministry of Education and Research (BMBF) Competence Network Asthma and COPD (ASCONET) and performed in collaboration with the German Center for Lung Research (DZL). The project is funded by the BMBF with grant number 01 GI 0881, and is supported by unrestricted grants from AstraZeneca GmbH, Bayer Schering Pharma AG, Boehringer Ingelheim Pharma GmbH & Co. KG, Chiesi GmbH, GlaxoSmithKline, Grifols Deutschland GmbH, MSD Sharp & Dohme GmbH, Mundipharma GmbH, Novartis Deutschland GmbH, Pfizer Pharma GmbH, Takeda Pharma Vertrieb GmbH & Co. KG, and Teva GmbH for patient investigations and laboratory measurements. The funding bodies had no involvement in the design of the study, or the collection, analysis or interpretation of the data.

Data sharing statement

COSYCONET is an ongoing long-term multi-center observational study and data are not intended to be freely available to the public. If, however, there is interest in analyzing specific questions, a formal request can be submitted to the study office, which will be evaluated by the steering committee on scientific grounds. There is no limitation except proven expertise in COPD studies.

Disclosure

Peter Alter, Barbara A Mayerhofer, Kathrin Kahnert, Henrik Watz, Benjamin Waschki, Frank Biertz, and Rudolf A Jörres report no conflicts of interest in this work. Stefan Andreas report grants and personal fees from Boehringer Ing and Pfizer, and personal fees from Novartis, Astra Zeneca, GSK, Chiesi, and Merini, outside the submitted work. Robert Bals report grants from German Federal Ministry of Education and Research (BMBF) Competence Network Asthma and COPD (ASCONET), during the conduct of the study, and grants and personal fees from AstraZeneca, Novartis, and Boehringer Ingelheim, and personal fees from GlaxoSmithKline, Grifols, and CSL Behring, outside the submitted work. Claus F Vogelmeier report grants and personal fees from AstraZeneca, Boehringer Ingelheim, GlaxoSmithKline, Grifols, and Novartis, personal fees from CSL Behring, Chiesi, Menarini, Mundipharma, Teva, and Cipla, and grants from Bayer Schering Pharma AG, MSD, and Pfizer, outside the submitted work. The authors report no other conflicts of interest regarding this work.