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Marijuana Smoking is Associated With Atrial Fibrillation
READERS’ COMMENTS Dual Antiplatelet Therapy After Coronary Artery Bypass Grafting: Does Off/On-Pump Play a Role? We read the systematic review by Nocerino et al1 discussing the effect of postoperative dual antiplatelet therapy (DAPT) on graft patency after coronary artery bypass grafting (CABG). We had earlier presented a pooled analysis of 11 studies (both observational and randomized controlled trials) evaluating the benefit of DAPT after CABG.2 We have also presented results specifically in patients undergoing offpump CABG (OPCABG). A recent study has presented an ad hoc analysis of the Randomized On/Off Bypass (ROOBY) trial.3 The ROOBY study is a randomized controlled trial comparing on- and OPCABG.4 Although they conclude that DAPT does not affect graft patency in the overall cohort, they found improvement in graft patency in multivariate analysis in patients treated with DAPT who underwent OPCABG (p ¼ 0.014). We conducted an updated meta-analysis of the 3 published randomized controlled trials3,5,6 incorporating only patients who underwent OPCABG. This demonstrated the significant benefit of DAPT (risk ratio for graft occlusion with DAPT 0.50, 95% confidence interval 0.42 to 0.60, p <0.01) in reducing vein graft occlusion. DAPT was also beneficial in reducing postoperative cardiac events (risk ratio 0.29, 95% confidence interval 0.11 to 0.72, p ¼ 0.008) and perioperative myocardial infarction (p ¼ 0.02). There is a wide variability in the level of anticoagulation targeted during OPCABG. A recent review demonstrated that many preferred partial heparin with or without protamine reversal.7 Although this method would reduce postoperative bleeding, it would likely create a more prothrombotic environment at the anastomosis, predisposing to platelet accumulation. Intracoronary shunts used during surgery may also create microvascular trauma subsequently leading to an increased tendency for platelet accumulation on the intima.8 These may be some reasons for the beneficial effect of DAPT in OPCABG.
We believe that DAPT is not without a small but finite risk of bleeding. Rather than adopting a uniform strategy, it is important to tailor this therapy to the individual patient. The use of DAPT with conventional CABG clearly presents conflicting results regarding vein graft patency; however, whenever possible, its use in patients undergoing OPCABG is to be recommended. Salil V. Deo, MS, MCh Surat, Gujarat, India Shannon M. Dunlay, MD, MSc Rochester, Minnesota Soon J. Park, MD Cleveland, Ohio 19 December 2013
1. Nocerino AG, Achenbach S, Taylor AJ. Metaanalysis of effect of single versus dual antiplatelet therapy on early patency of bypass conduits after coronary artery bypass grafting. Am J Cardiol 2013;112:1576e1579. 2. Deo SV, Dunlay SM, Shah IK, Altarabsheh SE, Erwin PJ, Boilson BA, Park SJ, Joyce LD. Dual anti-platelet therapy after coronary artery bypass grafting: is there any benefit? A systematic review and meta-analysis. J Card Surg 2013;28:109e116. 3. Ebrahimi R, Bakaeen FG, Uberoi A, Ardehali A, Baltz JH, Hattler B, Almassi GH, Wagner TH, Collins JF, Grover FL, Shroyer AL. Effect of clopidogrel use post coronary artery bypass surgery on graft patency. Ann Thor Surg 2013. 4. Hattler B, Messenger JC, Shroyer AL, Collins JF, Haugen SJ, Garcia JA, Baltz JH, Cleveland JC Jr, Novitzky D, Grover FL. OffPump coronary artery bypass surgery is associated with worse arterial and saphenous vein graft patency and less effective revascularization: results from the Veterans Affairs Randomized On/Off Bypass (ROOBY) trial. Circulation 2012;125:2827e2835. 5. Mannacio VA, Di Tommaso L, Antignan A, De Amicis V, Vosa C. Aspirin plus clopidogrel for optimal platelet inhibition following offpump coronary artery bypass surgery: results from the CRYSSA (prevention of Coronary arteRY bypaSS occlusion After off-pump procedures) randomised study. Heart 2012;98: 1710e1715. 6. Mujanovic E, Nurkic M, Caluk J, Terzic I, Kabil E, Bergsland J. The effect of combined clopidogrel and aspirin therapy after off-pump coronary surgery: a pilot study. Innovations (Phila) 2009;4:265e268. 7. Rasoli S, Zeinah M, Athanasiou T, Kourliouros A. Optimal intraoperative anticoagulation strategy in patients undergoing off-pump coronary artery bypass. Inter Cardiovas Thor Surg 2012;14:629e633.
Am J Cardiol 2014;113:1085e1086 0002-9149/14/$ - see front matter Ó 2014 Elsevier Inc. All rights reserved.
8. Hangler H, Mueller L, Ruttmann E, Antretter H, Pfaller K. Shunt or snare: coronary endothelial damage due to hemostatic devices for beating heart coronary surgery. Ann Thor Surg 2008;86:1873e1877. http://dx.doi.org/10.1016/j.amjcard.2013.12.010
Marijuana Smoking is Associated With Atrial Fibrillation In their recent review, Thomas et al1 provide a concise overview of the cardiovascular effects of marijuana smoking. In fact, marijuana may acutely affect the circulatory system triggering cardiovascular events. Most published reports have focused on incidents of acute coronary syndromes, acute cerebrovascular and peripheral vascular events, and more rarely, ischemia-induced ventricular arrhythmias. However, an increasing number of case reports indicate an association between cannabis use and atrial fibrillation (AF). In a systematic review published in 2008, we analyzed 6 reported cases.2 In all instances AF was of recent onset occurring shortly after marijuana smoking in young subjects.2 No patient had a structural heart disease and only 1 had a precipitating factor (hypertension), and all patients had a favorable outcome with no recurrence after cessation of marijuana smoking.2 Since 2008, we have come across 2 cases of marijuana-associated paroxysmal AF in our center, both cases in young patients without any co-morbidities. Moreover, a retrospective 6-year period analysis of young patients (defined as aged 45 years) with “lone” AF admitted to City Hospital, Birmingham, UK showed that in 3 of 88 cases marijuana was the precipitating factor.3 One of these patients had further paroxysms of the arrhythmia due to continuing use of cannabis.3 Of note, adrenergic stimulation and disturbances in atrial coronary or microvascular flow associated with marijuana smoking may facilitate AF development and perpetuation possibly because of increased pulmonary vein ectopy, enhanced atrial electrical remodeling, and increased dispersion of refractoriness.2
www.ajconline.org
1086
The American Journal of Cardiology (www.ajconline.org)
It should also be stressed that although this adverse event seems to be quite “benign” in young healthy subjects, it is apparently more “malignant” in older patients having other risk factors for thromboembolism. The exact incidence of AF related to marijuana smoking is difficult to be estimated. Given the euphoric and neuropsychological effects of marijuana that may alter or cover palpitations or other symptoms suggestive of AF, this issue becomes more complicated. It should also be borne in mind that due to social or legal reasons, most users of illicit drugs avoid seeking medical attention. In addition, many short episodes of AF may pass unnoticed. Taking into consideration all these notions, it could be reasonable to conclude that the burden of the problem is possibly underestimated. Panagiotis Korantzopoulos, MD, PhD Ioannina, Greece 30 December 2013
1. Thomas G, Kloner RA, Rezkalla S. Adverse cardiovascular, cerebrovascular, and peripheral vascular effects of marijuana inhalation: what cardiologists need to know. Am J Cardiol 2014;113:187e190. 2. Korantzopoulos P, Liu T, Papaioannides D, Li G, Goudevenos JA. Atrial fibrillation and marijuana smoking. Int J Clin Pract 2008;62: 308e313. 3. Krishnamoorthy S, Lip GY, Lane DA. Alcohol and illicit drug use as precipitants of atrial fibrillation in young adults: a case series and literature review. Am J Med 2009;122: 851e856.e3. http://dx.doi.org/10.1016/j.amjcard.2014.01.001
Adverse Cardiovascular, Cerebrovascular, and Peripheral Vascular Effects of Marijuana: What Cardiologists Need to Know We read the recent report Adverse Cardiovascular, Cerebrovascular, and
Peripheral Vascular Effects of Marijuana: What cardiologists need to know by Thomas et al.1 The investigators summarized the literature concerning the adverse vascular effects of marijuana, the most widely used illicit drug in the world. We would like to point out an omission in the review. In 2013, we published a study of 160 patients with ischemic stroke and transient ischemic attack aged 18 to 55 years and 160 age-, gender-, and ethnicitymatched control patients without cardiovascular or neurologic diagnoses.2 Cases and controls had urine screens for cannabis within 72 hours of hospital admission. Twenty-five patients (15.6%) with stroke and transient ischemic attack had positive cannabis drug screens. Thirteen control participants (8.1%) had positive cannabis screens. Cannabis use was associated with increased risk of ischemic stroke and/or transient ischemic attack in a logistic regression analysis adjusted for age, gender, and ethnicity (odds ratio 2.30, 95% confidence interval 1.08 to 5.08). However, an association independent of tobacco has not been confirmed as all but one of the patients who tested positive for cannabis also used tobacco. Finding an association is not the same as finding causality. However, we agree that it is important for cardiologists and other physicians caring for patients with vascular disease to be aware of this potential association. We suggest that younger patients presenting with acute cardiac and cerebral ischemia are screened for cannabis, particularly in cases when there are no other vascular risk factors. Those patients with positive screens could then be informed of a potential association between cannabis and vascular disease and be counseled
against further use. The wave of decriminalization of cannabis use in the United States and elsewhere in the world makes it imperative that further research is undertaken to clarify the relation between cannabis and vascular disease. Peter Alan Barber, PhD Sally Roberts, MBChB David A. Spriggs, MBChB Neil E. Anderson, MBChB Auckland, New Zealand 23 January 2014
1. Thomas G, Kloner RA, Rezkalla S. Adverse cardiovascular, cerebrovascular, and peripheral vascular effects of marijuana inhalation: what cardiologists need to know. Am J Cardiol 2014;113:187e190. 2. Barber PA, Pridmore HM, Krishnamurthy V, Roberts S, Spriggs DA, Carter KN, Anderson NE. Cannabis, ischemic stroke, and transient ischemic attack: a case-control study. Stroke 2013;44:2327e2329. http://dx.doi.org/10.1016/j.amjcard.2014.01.400
Erratum for Soufras et al. “Relation Between White Blood Cell Count and Infarct Size: What About Differential?” Am J Cardiol 2014;113:412 Re: Soufras GD, Hahali G, Kounis NG. Relation between white blood cell count and infarct size: what about differential? Am J Cardiol 2014 Jan 15;113(2):412 Should be changed to: Re: Soufras GD, Hahalis G, Kounis NG. Relation between white blood cell count and infarct size: what about differential? Am J Cardiol 2014 Jan 15;113(2):412 http://dx.doi.org/10.1016/j.amjcard.2014.01.003
We believe that DAPT is not without a small but finite risk of bleeding. Rather than adopting a uniform strategy, it is important to tailor this therapy to the individual patient. The use of DAPT with conventional CABG clearly presents conflicting results regarding vein graft patency; however, whenever possible, its use in patients undergoing OPCABG is to be recommended. Salil V. Deo, MS, MCh Surat, Gujarat, India Shannon M. Dunlay, MD, MSc Rochester, Minnesota Soon J. Park, MD Cleveland, Ohio 19 December 2013
1. Nocerino AG, Achenbach S, Taylor AJ. Metaanalysis of effect of single versus dual antiplatelet therapy on early patency of bypass conduits after coronary artery bypass grafting. Am J Cardiol 2013;112:1576e1579. 2. Deo SV, Dunlay SM, Shah IK, Altarabsheh SE, Erwin PJ, Boilson BA, Park SJ, Joyce LD. Dual anti-platelet therapy after coronary artery bypass grafting: is there any benefit? A systematic review and meta-analysis. J Card Surg 2013;28:109e116. 3. Ebrahimi R, Bakaeen FG, Uberoi A, Ardehali A, Baltz JH, Hattler B, Almassi GH, Wagner TH, Collins JF, Grover FL, Shroyer AL. Effect of clopidogrel use post coronary artery bypass surgery on graft patency. Ann Thor Surg 2013. 4. Hattler B, Messenger JC, Shroyer AL, Collins JF, Haugen SJ, Garcia JA, Baltz JH, Cleveland JC Jr, Novitzky D, Grover FL. OffPump coronary artery bypass surgery is associated with worse arterial and saphenous vein graft patency and less effective revascularization: results from the Veterans Affairs Randomized On/Off Bypass (ROOBY) trial. Circulation 2012;125:2827e2835. 5. Mannacio VA, Di Tommaso L, Antignan A, De Amicis V, Vosa C. Aspirin plus clopidogrel for optimal platelet inhibition following offpump coronary artery bypass surgery: results from the CRYSSA (prevention of Coronary arteRY bypaSS occlusion After off-pump procedures) randomised study. Heart 2012;98: 1710e1715. 6. Mujanovic E, Nurkic M, Caluk J, Terzic I, Kabil E, Bergsland J. The effect of combined clopidogrel and aspirin therapy after off-pump coronary surgery: a pilot study. Innovations (Phila) 2009;4:265e268. 7. Rasoli S, Zeinah M, Athanasiou T, Kourliouros A. Optimal intraoperative anticoagulation strategy in patients undergoing off-pump coronary artery bypass. Inter Cardiovas Thor Surg 2012;14:629e633.
Am J Cardiol 2014;113:1085e1086 0002-9149/14/$ - see front matter Ó 2014 Elsevier Inc. All rights reserved.
8. Hangler H, Mueller L, Ruttmann E, Antretter H, Pfaller K. Shunt or snare: coronary endothelial damage due to hemostatic devices for beating heart coronary surgery. Ann Thor Surg 2008;86:1873e1877. http://dx.doi.org/10.1016/j.amjcard.2013.12.010
Marijuana Smoking is Associated With Atrial Fibrillation In their recent review, Thomas et al1 provide a concise overview of the cardiovascular effects of marijuana smoking. In fact, marijuana may acutely affect the circulatory system triggering cardiovascular events. Most published reports have focused on incidents of acute coronary syndromes, acute cerebrovascular and peripheral vascular events, and more rarely, ischemia-induced ventricular arrhythmias. However, an increasing number of case reports indicate an association between cannabis use and atrial fibrillation (AF). In a systematic review published in 2008, we analyzed 6 reported cases.2 In all instances AF was of recent onset occurring shortly after marijuana smoking in young subjects.2 No patient had a structural heart disease and only 1 had a precipitating factor (hypertension), and all patients had a favorable outcome with no recurrence after cessation of marijuana smoking.2 Since 2008, we have come across 2 cases of marijuana-associated paroxysmal AF in our center, both cases in young patients without any co-morbidities. Moreover, a retrospective 6-year period analysis of young patients (defined as aged 45 years) with “lone” AF admitted to City Hospital, Birmingham, UK showed that in 3 of 88 cases marijuana was the precipitating factor.3 One of these patients had further paroxysms of the arrhythmia due to continuing use of cannabis.3 Of note, adrenergic stimulation and disturbances in atrial coronary or microvascular flow associated with marijuana smoking may facilitate AF development and perpetuation possibly because of increased pulmonary vein ectopy, enhanced atrial electrical remodeling, and increased dispersion of refractoriness.2
www.ajconline.org
1086
The American Journal of Cardiology (www.ajconline.org)
It should also be stressed that although this adverse event seems to be quite “benign” in young healthy subjects, it is apparently more “malignant” in older patients having other risk factors for thromboembolism. The exact incidence of AF related to marijuana smoking is difficult to be estimated. Given the euphoric and neuropsychological effects of marijuana that may alter or cover palpitations or other symptoms suggestive of AF, this issue becomes more complicated. It should also be borne in mind that due to social or legal reasons, most users of illicit drugs avoid seeking medical attention. In addition, many short episodes of AF may pass unnoticed. Taking into consideration all these notions, it could be reasonable to conclude that the burden of the problem is possibly underestimated. Panagiotis Korantzopoulos, MD, PhD Ioannina, Greece 30 December 2013
1. Thomas G, Kloner RA, Rezkalla S. Adverse cardiovascular, cerebrovascular, and peripheral vascular effects of marijuana inhalation: what cardiologists need to know. Am J Cardiol 2014;113:187e190. 2. Korantzopoulos P, Liu T, Papaioannides D, Li G, Goudevenos JA. Atrial fibrillation and marijuana smoking. Int J Clin Pract 2008;62: 308e313. 3. Krishnamoorthy S, Lip GY, Lane DA. Alcohol and illicit drug use as precipitants of atrial fibrillation in young adults: a case series and literature review. Am J Med 2009;122: 851e856.e3. http://dx.doi.org/10.1016/j.amjcard.2014.01.001
Adverse Cardiovascular, Cerebrovascular, and Peripheral Vascular Effects of Marijuana: What Cardiologists Need to Know We read the recent report Adverse Cardiovascular, Cerebrovascular, and
Peripheral Vascular Effects of Marijuana: What cardiologists need to know by Thomas et al.1 The investigators summarized the literature concerning the adverse vascular effects of marijuana, the most widely used illicit drug in the world. We would like to point out an omission in the review. In 2013, we published a study of 160 patients with ischemic stroke and transient ischemic attack aged 18 to 55 years and 160 age-, gender-, and ethnicitymatched control patients without cardiovascular or neurologic diagnoses.2 Cases and controls had urine screens for cannabis within 72 hours of hospital admission. Twenty-five patients (15.6%) with stroke and transient ischemic attack had positive cannabis drug screens. Thirteen control participants (8.1%) had positive cannabis screens. Cannabis use was associated with increased risk of ischemic stroke and/or transient ischemic attack in a logistic regression analysis adjusted for age, gender, and ethnicity (odds ratio 2.30, 95% confidence interval 1.08 to 5.08). However, an association independent of tobacco has not been confirmed as all but one of the patients who tested positive for cannabis also used tobacco. Finding an association is not the same as finding causality. However, we agree that it is important for cardiologists and other physicians caring for patients with vascular disease to be aware of this potential association. We suggest that younger patients presenting with acute cardiac and cerebral ischemia are screened for cannabis, particularly in cases when there are no other vascular risk factors. Those patients with positive screens could then be informed of a potential association between cannabis and vascular disease and be counseled
against further use. The wave of decriminalization of cannabis use in the United States and elsewhere in the world makes it imperative that further research is undertaken to clarify the relation between cannabis and vascular disease. Peter Alan Barber, PhD Sally Roberts, MBChB David A. Spriggs, MBChB Neil E. Anderson, MBChB Auckland, New Zealand 23 January 2014
1. Thomas G, Kloner RA, Rezkalla S. Adverse cardiovascular, cerebrovascular, and peripheral vascular effects of marijuana inhalation: what cardiologists need to know. Am J Cardiol 2014;113:187e190. 2. Barber PA, Pridmore HM, Krishnamurthy V, Roberts S, Spriggs DA, Carter KN, Anderson NE. Cannabis, ischemic stroke, and transient ischemic attack: a case-control study. Stroke 2013;44:2327e2329. http://dx.doi.org/10.1016/j.amjcard.2014.01.400
Erratum for Soufras et al. “Relation Between White Blood Cell Count and Infarct Size: What About Differential?” Am J Cardiol 2014;113:412 Re: Soufras GD, Hahali G, Kounis NG. Relation between white blood cell count and infarct size: what about differential? Am J Cardiol 2014 Jan 15;113(2):412 Should be changed to: Re: Soufras GD, Hahalis G, Kounis NG. Relation between white blood cell count and infarct size: what about differential? Am J Cardiol 2014 Jan 15;113(2):412 http://dx.doi.org/10.1016/j.amjcard.2014.01.003