Worsened impact of heart attacks among heavy smokers

The risk of death or poor prognosis after a heart attack is more than 20-fold higher in smokers with exhaled carbon monoxide levels above 13 ppm, indicating heavy smoking and inhalation of smoke. That's the finding of late-breaking research presented at ESC Congress 2022.

During a two-week period in April 2021, expiratory carbon monoxide was measured within two hours of admission in all consecutive adults hospitalized for acute cardiac events in 39 intensive cardiac care units (ICCU) in France. A total of 1,379 patients were studied.

Patients were asked about their smoking status. 33% were non-smokers, 39% were former smokers, and 27% were active smokers. Carbon monoxide level was similar in non-smokers and former smokers and significantly higher in active smokers. The investigators analyzed the association between carbon monoxide level and the primary outcome of in-hospital major adverse events, which was a composite of death, resuscitated cardiac arrest, or cardiogenic shock. A total of 4.2% of patients experienced a major adverse event while in the hospital. Carbon monoxide level was significantly associated with major adverse events in active smokers.

The researchers identified 13 ppm as the best threshold for predicting a worse prognosis. The odds of a major adverse event were 23-fold higher in smokers with a carbon monoxide level above 13 ppm, as compared with 13 ppm or below, after adjustment for factors that could influence the relationship including age, sex, diabetes, smoking status, history of cardiovascular disease, chronic kidney disease, history of cancer, and reason for admission. In smokers with a carbon monoxide level of 13 ppm or below, the rate of major adverse events was similar to non or former smokers. Nearly 19% of active smokers had a carbon monoxide level above 13 ppm compared with less than 2% of non or former smokers.

Ref:

Professor Patrick Henry et al, ESC Congress 2022