Baseline. Cardiovascular diseases are among the most important diseases that cause common co-morbidities in patients with chronic obstructive pulmonary disease (COPD). Diagnosis of heart failure as a cause of deterioration or as an associated disease in patients with COPD is very important for the proper and optimal patient management.Objectives.We aimed to determine the frequency of left ventricular dysfunction in patients with acute exacerbation of COPD. We wanted to evaluate the role of cardiac biomarkers in differential diagnosis of acute exacerbation and risk assessment for re-hospitalization. Method.Our prospective study included 127 consecutive patients (70 10 years, 70% male) with severe or very severe COPD (110 patients –87%). Upon admission of patients echocardiography was performed. On admission, discharge and 7-10 days after discharge blood was drawn to determineN-terminal brain natriuretic peptide (NT-proBNP), troponin and cystatin. Information about demographic characteristics, concomitant disease, and pharmacological management was retrieved from medical records. Re-hospitalisations were observed 180 days after discharge. Numeric variables were presented with mean and standard deviation. Attribute variables were presented as number and percentage shares. Differences between variables were analyzed using Student’s t-test for independent samples, paired t-test and χ2 test. Frequency and possible factors of re-hospitalization were analyzed with Kaplan Meier method and Cox proportional risk model. Značaj ehokardiografije i NT-proBNP-a u bolesnika s akutnim pogoršanjem kronične opstruktivne plućne bolesti. VIResults.Normal left ventricular ejection fraction had 110 (87%) patients. Left ventricular dysfunction was observed in 70 (55%) patients, where most of them had abnormal left ventricular filling. NT-proBNP was elevated at admission in 76 (60%) patients and in remission in 46 (36%) patients. Troponin was elevated at admission in 35 (28%) patients and at discharge in 24 (19%) patients. Higher concentration of NT-proBNP (p=0.004, 0.007 and 0.019) was observed in patients with left ventricular dysfunction. There was a significant reduction in concentration of NT-proBNP in both groups of patients; from admission until discharge, or 7-10 days after discharge (p=0.006 and 0.019). Concentration of troponin T was not significantly different during the treatment of patients (p=0.518, 0.185 and 0.299), however significant reduction occurred in the group with left ventricular dysfunction (p=0.043). Patients were assessed 6 months after discharge and 53 (42%) patients were re-hospitalized. The risk of hospitalization was not associated with the level of disease by Gold, left ventricular dysfunction or concentration of NT-proBNP. Concentration of troponin at discharge was the only factor to predict adverse prognosis (hazard ratio 1.95, 95% confidence interval 1.04 –3.64). Of 31 patients with a prior diagnosis of heart failure 19 (61%) patients were receiving ACE inhibitors and 14 (45%) patients beta–blocker. Target dose of ≥50% of the ACE inhibitor received 12 (63%) patients, target dose of ≥50% of beta-blocker received 7 (50%) patients.Conclusions.In patients with acute exacerbation of COPD, left ventricular dysfunction is frequent. Determination of cardiac biomarkers is important to identify the cause of clinical deterioration in patients with COPD. Concentration of troponin at discharge was the only independent prognostic factor for re-hospitalization. Treatment of cardiac dysfunction in patients with COPD is at the moment not in accordance with guidelines.