The aim of this study is to assess whether prophylactic treatment with metoprolol or losartan is able to reduce the incidence of atrial fibrillation (AF) in patients undergoing thoracic surgery for lung cancer, showing elevated plasma levels in NT probrain natriuretic peptide (NT-proBNP), measured in the perioperative period.

Postoperative atrial fibrillation is one of the most common complication after thoracic surgery for lung cancer, with an incidence ranging from 8 to 20% after lobectomy and up to 42% after pneumonectomy.

In a recent study we demonstrated that a high perioperative plasma levels of NT-proBNP is able to identify patients at risk for AF (incidence of 65%).

It has also been demonstrated that the renin-angiotensin system may play an important role in the pathophysiology of atrial fibrillation and that angiotensin converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARBs) are able to prevent atrial fibrillation in patients with heart failure, after myocardial infarction, in hypertensive patients and after electrical cardioversion.

Inclusion Criteria:

• Patients of both sexes with age ≥ 18 years
• Thoracic surgery for lung cancer
• Evidence of elevated perioperative NT-proBNP
• Written informed consent

Exclusion Criteria:

• Hypersensitivity and / or intolerance to metoprolol or losartan
• History of heart failure
• Left ventricular ejection fraction <50% measured by echocardiographic techniques (Simpson rule)
• Permanent atrial fibrillation
• Antiarrhythmic therapy
• Current therapy with beta-blockers, angiotensin II receptor blockers and angiotensin-converting enzyme inhibitors
• Systolic blood pressure <95 mmHg
• Pregnant and lactating women

Additional exclusion criteria for therapy with beta-blocker:

• History of sick sinus syndrome, evidence of AV-block grade II or greater
• Heart rate <65 b / m
• History of bronchial asthma, severe bronchopneumopathy, evidence of bronchospasm