Alcohol abuse may increase the risk of heart attacks and other cardiac problems even in people who don't have a family history of heart disease or other known risk factors, a study suggests.
After accounting for established risk factors for heart disease such as smoking, obesity and diabetes, alcohol abuse was associated with a 40 percent higher risk of heart attack, the study found.
Excessive drinking was also tied to a two-fold greater risk of atrial fibrillation, or an irregular rapid heartbeat, and a 2.3-fold increased risk of congestive heart failure, a chronic pumping disorder.
Even though some previous research has linked an occasional or even daily drink to better heart health, these findings should put to rest any notion that drinking more is better for our health, said senior study author Dr. Gregory Marcus of the University of California, San Francisco.
"Excessive drinking might be ostensibly `justified' by some individuals because of the purported heart benefits," Marcus said by email.
"We have shown here that not only does excessive alcohol substantially increase the risk for atrial fibrillation and heart failure, but also heart attack, the one phenomenon that previous data has suggested might be mitigated by moderate alcohol consumption," Marcus added.
To assess the connection between alcohol abuse and heart problems, Marcus and colleagues analyzed data on more than 14.7 million California adults who had surgery, emergency or inpatient hospital care from 2005 to 2009.
About 1.8 percent of the people in the study, or approximately 268,000 patients, had been diagnosed with alcohol abuse.
The increased risk of heart attack, atrial fibrillation and congestive heart failure associated with alcohol abuse in the study were similar in magnitude to other well-recognized modifiable risk factors such as diabetes, high blood pressure and obesity, researchers report in the Journal of the American College of Cardiology.
Completely eradicating alcohol abuse would result in more than 73,000 fewer atrial fibrillation cases, 34,000 fewer heart attacks, and 91,000 fewer patients with congestive heart failure in the U.S. alone, the researchers estimated.
The study is observational and doesn't prove drinking causes heart problems.
Another limitation of the study is that the data on patients diagnosed with alcohol abuse problems didn't specify how much individual people drank, the authors note. It's also possible that some people in the study were excessive drinkers but not diagnosed as alcohol abusers in the data, which also limits the ability to specify the amount of alcohol that may be harmful.
Even so, it's possible that the current study with its broad population of hospitalized patients may have identified alcohol-related heart problems that previous research missed by focusing on a narrower subset of people, Dr. Michael Criqui, of the University of California, San Diego, writes in an accompanying editorial.
Earlier studies may have found drinking protective against heart attack and other heart problems because they included patients with a stable, healthier lifestyle, Criqui writes. By contrast, the broad cross-section of adults in the current study included more sick people who might not be as health-conscious.
"The most recent evidence casts doubt on whether there are any heart benefits of light to moderate drinking," Criqui said by email.
"No randomized clinical trials have been done, and they would be technically difficult to do on this question," Criqui added. "Studies do show benefit to quitting drinking, and the sooner the better, as over time the damage may be irreversible."