Non-smokers are more prone to pulmonary oedema than smokers during acute coronary syndrome.

OBJECTIVES

Acute coronary syndrome (ACS) patients are prone to develop pulmonary oedema with varied degree of hypoxaemia. The aim was to compare the risk for pulmonary oedema and related complications during ACS amongst non-smokers vs. smokers.

METHODS

Prospective, observational study was performed in consecutive 68 patients presenting with ACS. They were divided into two groups; group 1 (n = 33) non-smokers and group 2 (n = 35) chronic smokers. Standard conservative treatment was given to maintain mean arterial pressure >or= 60 mmHg, oxygen saturation > 95%. The bedside chest x-ray was graded for Battler grading (0-4) for pulmonary oedema. All patients were evaluated for troponin, serial creatinine kinase, echocardiography, arterial blood gas, renal function and correlated with inotropes requirement, active respiratory support, coronary care unit (CCU) stay and hospital outcome.

RESULTS

Patients in both the groups had similar cardiac involvement for cardiothoracic ratio, troponin, ejection fraction and creatinine kinase muscle and brain (CK-MB). The bedside chest x-ray revealed significant (p < 0.05) lung oedema grades (3 and 4) in 60% non-smokers (group 1) vs. smokers (11%). These patients (group 1) also presented with significant (p < 0.001) hypoxaemia (lower PaO(2)/FiO(2)-201 +/- 44), metabolic acidosis (higher lactate; 2.1 +/- 0.72 mmol/l, base deficit; -5.1 +/- 4.8) and hypocarbia (28 +/- 2.9 mmHg) than smokers (group 2). The risk estimates for active respiratory support (OR =1.716) and inotrope use (OR = 1.836) was three times higher in non-smokers than smokers.

CONCLUSIONS

The higher degree of pulmonary oedema and hypoxemia probably contributed to poor short-term outcome in non-smokers than smokers. It would be important to recognise and treat hypoxaemia in non-smokers during ACS.