Incident Atrial Fibrillation and Intoxicants

I remain very interested in the cardiac and brain complications of medications and substances that are commonly used to get high or create altered states.  I am also very interested in the popular trend to characterize cannabis as some previously undiscovered medication that can cure everything ranging from anxiety to obstructive sleep apnea.  I was naturally interested when I saw this paper (1) looking at the issue of incident atrial fibrillation and common intoxicants.

The authors examine a very large database in California that included anyone who had been seen in an emergency department, ambulatory surgery center, or hospital over a period of 10 years (2005-2015).  After they eliminate minors, subjects with persistent atrial fibrillation, and subjects with missing data they had a total of 23,561,884 people. 998,747 of those people had incident atrial fibrillation (defined as the first encounter for atrial fibrillation).  Since their study design is a retrospective observational study they also recorded substance use was considered present if Substance use was considered present if there was coding for any indication of use of methamphetamine, cocaine, opiates, or cannabis.  Knowing the atrial fibrillation and substance use diagnoses – the authors calculate the hazard ratio for each of the substances of interest.

Hazard ratios are basically the ratio of the people exposed to intoxicants who developed atrial fibrillation over the unexposed who developed atrial fibrillation.  So any number greater than 1 means that the population exposed to intoxicants had greater risk.  The corrected hazard ratios were noted to be 1.86 (methamphetamine), 1.74 (opioids), 1.61 (cocaine), and 1.35 cannabis. The authors adjusted for common atrial fibrillation risk factors and ran an additional negative control analysis and looked at the scatter of data pints for these 4 substances and hazard ratios of developing appendicitis, connective and soft tissue sarcoma, and renal cell carcinoma and showed no consistent pattern for these illnesses.

There are a couple of interesting considerations relevant to this study.  The first is the mechanism of action in each case. With stimulants there is a direct hyperadrenergic effects and depending on the individual and dose of the drug varying degrees of tachycardia, palpitations, and hypertension.  Long term users frequently end up with cardiomyopathy from these effects and in some cases ventricular arrhythmias and congestive heart failure. There can also be acute vascular effects like ischemia either due to the increased cardiac demand or pre-existing arteriosclerosis. Atrial fibrillation has not typically been placed in that group of morbidities from stimulant use. Patient with atrial fibrillation often notice emotional precipitants for discrete episodes or atrial fibrillation although a recent study showed that the only reliable precipitant was alcohol use (2). There were significant limitations with that study with attrition and length of the study although I generally agree that alcohol is a clear participant.  Precipitants need to be carefully approached and I suspect that attentive physicians have noted variable phenomenology on an individual basis. 

The high hazard ratio for opioids is a little puzzling. Hyperadrenergic states can occur with the euphorigenic effects and withdrawal effects as well. Direct comparison with stimulants may be difficult due to rapid dose escalation and some degree of tachyphylaxis.  Cannabis is not surprising to me at all. Many initial cannabis smokers notice that their heart is pounding and don’t know why.  They find it unexpected given the conventional wisdom that cannabis is supposed to be a benign substance. Many initial users also get increased anxiety and, in some cases, have a panic attack that may be due to the cardiac sensations. The primary heart pounding sensation is because cannabis causes hypotension and they are experiencing reflex tachycardia. The effects may be less predictable because cannabis use can affect both sympathetic and parasympathetic pathways that can potentiate arrhythmias. A case report of cannabis induced atrial flutter (3) was described as occurring in a woman with a history of hypertension that eventually had to be terminated by an intravenous antiarrhythmic.   

Atrial fibrillation and other cardiac arrhythmias are another good reason for avoiding intoxicants including alcohol (in the supplementary analysis alcohol had a Hazard Ratio of 2.37).  It could be argued that it is basically a numbers game – since most people who use these intoxicants do not develop incident atrial fibrillation.  As of this moment, even if you have had your DNA analyzed for what are known about atrial fibrillation genes – you can’t be certain that you are not susceptible to the problem. And as outlined above there are many additional cardiac problems and that are possible from using these compounds.  The safest path is to avoid these intoxicants all together.

 

George Dawson, MD, DFAPA

 

 

References:

1:  Lin AL, Nah G, Tang JJ, Vittinghoff E, Dewland TA, Marcus GM. Cannabis, cocaine, methamphetamine, and opiates increase the risk of incident atrial fibrillation. Eur Heart J. 2022 Oct 18:ehac558. doi: 10.1093/eurheartj/ehac558. Epub ahead of print. PMID: 36257330.

2: Marcus GM, Modrow MF, Schmid CH, Sigona K, Nah G, Yang J, Chu TC, Joyce S, Gettabecha S, Ogomori K, Yang V, Butcher X, Hills MT, McCall D, Sciarappa K, Sim I, Pletcher MJ, Olgin JE. Individualized Studies of Triggers of Paroxysmal Atrial Fibrillation: The I-STOP-AFib Randomized Clinical Trial. JAMA Cardiol. 2022 Feb 1;7(2):167-174. doi: 10.1001/jamacardio.2021.5010. PMID: 34775507; PMCID: PMC8591553.

3: Fisher BA, Ghuran A, Vadamalai V, Antonios TF. Cardiovascular complications induced by cannabis smoking: a case report and review of the literature. Emerg Med J. 2005 Sep;22(9):679-80. doi: 10.1136/emj.2004.014969. PMID: 16113206; PMCID: PMC1726916. [full text]