Marijuana use may be linked to temporarily weakened heart muscle
November 13, 2016
Science Daily/American Heart Association
Active marijuana use may double the risk of stress cardiomyopathy, an uncommon heart muscle malfunction that can mimic heart attack symptoms, according to research presented at the American Heart Association's Scientific Sessions 2016.
The researchers found that marijuana users were almost twice as likely to develop stress cardiomyopathy compared to non-users, even after taking other cardiovascular risk factors into consideration. Active marijuana use was identified either by information provided by the patient in their medical history, or by a marker in the patient's urine.
"The effects of marijuana, especially on the cardiovascular system, are not well known yet. With its increasing availability and legalization in some states, people need to know that marijuana may be harmful to the heart and blood vessels in some people," said Amitoj Singh, M.D. study co-author and chief cardiology fellow at St. Luke's University Health Network in Bethlehem, Pennsylvania.
Stress cardiomyopathy is a sudden, usually temporary, weakening of the heart muscle that reduces the heart's ability to pump, leading to chest pain, shortness of breath, dizziness and sometimes fainting.
Data from the Nationwide Inpatient Sample identified 33,343 people who were hospitalized with stress cardiomyopathy between 2003-2011 in the United States. Of those, 210 (less than one percent) were also identified as marijuana users.
Compared with non-users, researchers found that marijuana users were more likely to be younger, male with fewer cardiovascular risk factors, including less high blood pressure, diabetes and high cholesterol.
However, despite being younger and with fewer cardiovascular risk factors than non-users, during stress cardiomyopathy the marijuana users were significantly more likely to go into cardiac arrest (2.4 percent vs. 0.8 percent) and to require an implanted defibrillator to detect and correct dangerously abnormal heart rhythms (2.4 percent vs. 0.6 percent).
"This development of stress cardiomyopathy in younger patients who used marijuana suggests a possible link that needs to be further investigated," said Sahil Agrawal, M.D., co-author of the paper and also a chief cardiology fellow at St. Luke's.
Marijuana users were more likely than non-users to have a history of depression (32.9 percent vs. 14.5 percent), psychosis (11.9 percent vs. 3.8 percent), anxiety disorder (28.4 percent vs. 16.2 percent), alcoholism (13.3 percent vs. 2.8 percent), tobacco use (73.3 percent vs. 28.6 percent) and multiple substance abuse (11.4 percent vs. 0.3 percent). Because some of these can increase the risk of stress cardiomyopathy, the researchers adjusted for known risk factors to investigate the association between marijuana use and stress cardiomyopathy.
"If you are using marijuana and develop symptoms such as chest pain and shortness of breath, you should be evaluated by a healthcare provider to make sure you aren't having stress cardiomyopathy or another heart problem," Singh said.
The study has some limitations. Because this was a retrospective study, the researchers could not determine how frequently the marijuana users were using marijuana, or what the timeframe was between the use of marijuana and occurrence of stress cardiomyopathy. Observational studies are not designed to prove cause and effect; therefore, it cannot be said that marijuana is or is not a direct cause of stress cardiomyopathy. In addition, because the database the researchers used reports regional but not state-by-state statistics, the researchers could not analyze whether possibly marijuana-related heart problems are increasing where use is legal.
https://www.sciencedaily.com/releases/2016/11/161113160447.htm
Marijuana use associated with increased risk of stroke, heart failure
As marijuana legalization spreads, better understanding of side effects is needed
March 9, 2017
Science Daily/American College of Cardiology
Using marijuana raises the risk of stroke and heart failure even after accounting for demographic factors, other health conditions and lifestyle risk factors such as smoking and alcohol use, according to research scheduled for presentation at the American College of Cardiology's 66th Annual Scientific Session.
Coming at a time when marijuana, medically known as cannabis, is on track to become legal for medical or recreational use in more than half of U.S. states, this study sheds new light on how the drug affects cardiovascular health. While previous marijuana research has focused mostly on pulmonary and psychiatric complications, the new study is one of only a handful to investigate cardiovascular outcomes.
"Like all other drugs, whether they're prescribed or not prescribed, we want to know the effects and side effects of this drug," said Aditi Kalla, MD, Cardiology Fellow at the Einstein Medical Center in Philadelphia and the study's lead author. "It's important for physicians to know these effects so we can better educate patients, such as those who are inquiring about the safety of cannabis or even asking for a prescription for cannabis."
The study drew data from the Nationwide Inpatient Sample, which includes the health records of patients admitted at more than 1,000 hospitals comprising about 20 percent of U.S. medical centers. Researchers extracted records from young and middle-aged patients -- age 18-55 years -- who were discharged from hospitals in 2009 and 2010, when marijuana use was illegal in most states.
Marijuana use was diagnosed in about 1.5 percent (316,000) of more than 20 million health records included in the analysis. Comparing cardiovascular disease rates in these patients to disease rates in patients not reporting marijuana use, researchers found marijuana use was associated with a significantly increased risk for stroke, heart failure, coronary artery disease and sudden cardiac death.
Marijuana use was also linked with a variety of factors known to increase cardiovascular risk, such as obesity, high blood pressure, smoking and alcohol use. After researchers adjusted the analysis to account for these factors, marijuana use was independently associated with a 26 percent increase in the risk of stroke and a 10 percent increase in the risk of developing heart failure.
"Even when we corrected for known risk factors, we still found a higher rate of both stroke and heart failure in these patients, so that leads us to believe that there is something else going on besides just obesity or diet-related cardiovascular side effects," Kalla said. "More research will be needed to understand the pathophysiology behind this effect."
Research in cell cultures shows that heart muscle cells have cannabis receptors relevant to contractility, or squeezing ability, suggesting that those receptors might be one mechanism through which marijuana use could affect the cardiovascular system. It is possible that other compounds could be developed to counteract that mechanism and reduce cardiovascular risk, Kalla said.
Because the study was based on hospital discharge records, the findings may not be reflective of the general population. The study was also limited by the researchers' inability to account for quantity or frequency of marijuana use, purpose of use (recreational or medical), or delivery mechanism (smoking or ingestion).
Kalla suggested that the growing trend toward legalization of marijuana could mean that patients and doctors will become more comfortable speaking openly about marijuana use, which could allow for better data collection and further insights into the drug's effects and side effects.
https://www.sciencedaily.com/releases/2017/03/170309142318.htm