Patients who quit smoking after an acute MI had improvements in their health-related quality of life and mental health, as well as reductions in angina, according to an analysis of two multicenter, prospective cohort studies.

Within a year, the risk of angina and the general mental health status of patients who quit smoking after their MI were similar to patients who never smoked. In addition, patients who quit smoking before their MI had a similar quality of life compared with patients who never smoked.

The researchers adjusted for numerous variables, including age, sex, comorbidities, in-hospital treatments, post-MI treatments, medications, sociodemographics and psychosocial factors. Results were published online in Circulation: Cardiovascular Quality and Outcomes on Aug. 25.

“The benefit of our study is that we very rigorously did a multivariable, sequential analysis of adjustments,” Sharon Cresci, MD, one of the study’s authors and an assistant professor of medicine at Washington University in St. Louis, told Cardiovascular Business. “When we did this huge amount of adjusting for all other factors you think might impact on this, there still was this gradation in association. I think it just shows how strong this association is and how much it matters when you stop smoking. You still can have an impact by stopping smoking right after your heart attack.”

When admitted to the hospital, 29 percent of patients were life-long nonsmokers, 34 percent were former smokers who quit before their acute MI and 37 percent had smoked within 30 days of their acute MI.

Of the patients who were current smokers at the time of their acute MI, 46 percent quit smoking within a year and were considered recent quitters. Cresi, who had previously evaluated the role that genetics plays in patients after MI, said some patients are predisposed to continue smoking. She is currently the principal investigator of an ongoing trial that’s evaluating whether genotype-guided therapy could improve the ability of patients to be able to stop smoking.

“There are certain genetic predispositions to having much more difficulty quitting smoking,” Cresci told Cardiovascular Business. “I wish we could change that number [of people who quit] more. I wish we had more tools to change the number, but from what I understand, it’s very, very difficult to stop smoking. We’re trying very actively to provide more and more support systems for people to stop smoking.”

Previous research showed that stopping smoking after an MI decreases the risk of mortality and recurrent MI by 30 percent to 50 percent. In fact, hospitals are required to tell patients with an acute MI about the benefits of stopping smoking before they are discharged. Examples of smoking cessation programs include counseling or nicotine replacement therapy.

In this analysis, the researchers evaluated data from the PREMIER (Prospective Registry Evaluating Myocardial Infarction: Events and Recovery) and TRIUMPH (Translational Research Investigating Underlying disparities in acute Myocardial infarction Patients’ Health Status) studies.

The PREMIER study enrolled 2,498 patients with acute MI from 19 U.S. hospitals between January 2003 and June 2004, while the TRIUMPH study enrolled 4,340 patients with acute MI from 24 U.S. hospitals between June 2005 and December 2008.

The final combined analysis included 4,003 patients. Saint Luke’s Mid America Heart Institute coordinated both studies, which had identical inclusion and exclusion criteria.

Researchers obtained data on smoking status and health status at baseline and conducted follow-up interviews with survivors at one, six and 12 months after they had an acute MI. Patients in the study were eligible if they survived for at least a year and were not discharged to another acute-care facility or hospice against medical advice.

To assess health-related quality of life, the researchers used the Seattle Angina Questionnaire and the Medical Outcomes Study 12-item Short Form.

Cresci said the results were generalizable to a broad population because the studies included Veterans Affairs hospitals, private practices and academic medical centers across the U.S.

“One of the motivations was to have a cross-sectional representation of all types of healthcare facilities across the country,” she said. “It’s racially diverse, it’s socioeconomically diverse and it doesn’t just [include] your elite medical research institutions.”