Primary Care Management of Multimorbidity: COPD, for Example

Patients seen in primary care are increasingly complex as many live longer but with chronic conditions that each require focused management. This complexity, or multimorbidity, characterizes a significant, and significantly expanding demographic.The patient with chronic obstructive pulmonary disease (CODP) is a textbook example of this “type” given the well-known association of cardiovascular disease (CVD), including heart failure, coronary artery disease and pulmonary hypertension (cor pulmonale) with COPD. The COPD patient may also have diabetes and chronic kidney disease, all physiologically overlapping with exacerbation of any single condition increasing the potential for morbidity many-fold.

Two studies presented this week at CHEST 2015, the American College of Chest Physicians annual meeting, in Montreal, reviewed an effort to refine risk factors predictive of worsening cardiovascular outcomes in patients admitted for acute exacerbations of COPD (AECOPD). The first study was from the Mayo Clinic Database and the other from a New Zealand study population.

The Mayo Clinic study is a five-year retrospective review that looked into the association of left ventricular hypertrophy (LVH) with AECOPD in 615 patients. LVH was defined as an LV mass index (LVMI) >95 g/m² in women and >115 g/m² in men, as determined by echocardiogram. Two-hundred and sixty four patients in the study group had LVH on admission for AECOPD and 351 were admitted for AECOPD without LVH. Baseline characteristics were similar in both patient groups: COPD severity, home O₂ use, short-acting and long-acting ß₂-agonist use as well as smoking status. The clinical outcomes were similar between these groups with respect to need for and duration of noninvasive mechanical ventilation (MV), failure of noninvasive ventilation (NIV),  reintubation at 48 hours, intensive care unit length of stay (LOS), total LOS, and in-hospital mortality. However, patients with LVH had significantly higher brain natriuretic peptide (BNP) and creatinine levels, as well as lower left ventricular ejection fractions. The study concluded that LVH per se, was not associated with increased LOS, need for supportive ventilation, or in-hospital mortality.

The New Zealand study focused on the relationship between the use of nebulized bronchodilators during an AECOPD and an increase in cardiovascular biomarkers-specifically N-terminal prohormone-BNP (proBNP) and troponin T.

The study included 176 patients who presented with AECOPD. Serum biomarker levels were obtained on admission and at 12 and 72 hours and finally at 30 days. Their results demonstrated an increase in both proBNP and troponin T that continued after admission and after cessation of nebulized bronchodilators. A study limitation was that the dosage and duration of action of the bronchodilators prescribed in New Zealand are higher and longer, respectively, than the standard in the U.S.

Primary care is experiencing a “darned if you do, darned if you don’t” analogy. Treatments for COPD may aggravate cardiac ischemia. COPD exacerbations may temporarily lower renal function. The next few years will give us more information on multimorbidity, and how we have to adjust therapy for these complex patients we see every day.

Shafuddin E, Vallabhajosyula S. COPD and the Heart. Presentation at: American College of Chest Physicians-CHEST 2015; October 26, 2015; Montreal, Canada.

References:

Buurman BM, Frenkel WJ, Abu-Hanna A, Parlevliet JL, de Rooij SE.  Acute and chronic diseases as part of multimorbidity in acutely hospitalized older patients. Eur J Intern Med. 2015 Oct 14. pii: S0953-6205(15)00327-1. doi: 10.1016/j.ejim.2015.09.021. [Epub ahead of print]

Barakat MF, McDonald HI, Collier TJ, et al. Acute kidney injury in stable COPD and at exacerbation. Int J Chron Obstruct Pulmon Dis. 2015 Sep 28;10:2067-77. doi: 10.2147/COPD.S88759. eCollection 2015.

Mueller C, Laule-Kilian K, Frana B, et al. Use of B-type natriuretic peptide in the management of acute dyspnea in patients with pulmonary disease. Am Heart J. 2006;151:471-477.