Highlights from the American College of Cardiology’s 2011 Annual Scientific Session and Innovation in Intervention: i2 Summit 2011 include stenting following CABG, yoga reducing AF, restless legs syndrome linked to CVD, and RF ablation for atrial fibrillation.
» Restless Legs Syndrome Linked to Heart Problems
» Stents & the Prevention of Major Adverse Events
» RF Ablation Beneficial for AF Patients
» Lung Transplants & Atrial Flutter
» Can Yoga Reduce Atrial Fibrillation Episodes?
Restless Legs Syndrome Linked to Heart Problems [back to top]
The Particulars: As the population continues to age, there has been an observed increase in the prevalence of sleep-related disorders and cardiovascular disease (CVD). Some studies have suggested that there might be a correlation between restless legs syndrome (RLS) and CVD. The recognition of frequent periodic leg movement during sleep as a potential modifiable risk factor for left ventricular hypertrophy may offer another target to help reduce the burden of CVD and associated complications.
Data Breakdown: A study was conducted in 584 patients who were referred to a sleep lab for polysomnography and had baseline echocardiography. According to electromyography, 45% of patients experienced more than 35 periodic leg movements per hour (the threshold considered severe). Patients with more than 35 bursts of leg movement per hour while sleeping carried a 1.85-fold elevated risk of severe left ventricular hypertrophy. When compared with those who did not have severe periodic leg movements during sleep, those who did had more evidence of structural heart problems, including, higher left ventricular mass on average, higher left ventricular mass index, thicker interventricular septum, and thicker posterior wall.
Take Home Pearls: RLS characterized by frequent leg movements during sleep appears to be linked to structural heart problems. The association between RLS and cardiac problems was strong, but whether it is causal or treatable remains unclear and warrants further investigation.
Stents & the Prevention of Major Adverse Events [back to top]
The Particulars: Few studies have assessed differences in clinical outcomes among patients with coronary artery lesions and how they respond to treatment with different types of stents for blockages in saphenous vein grafts. Of the available evidence, trials have yielded mixed results about the relative safety and efficacy of drug-eluting and bare-metal stents in these patients following CABG.
Data Breakdown: A study randomized 610 patients to one of three drug-eluting stents or a bare-metal stent. All patients had ischemic symptoms or evidence of myocardial ischemia as well as at least 50% stenosis in a saphenous vein graft. Most patients (60%) presented with stable angina, and half had a history of myocardial infarction (MI). At 1 year, the rate of all-cause death, MI, or target lesion revascularization was significantly lower in the patients who received a drug-eluting stent when compared with receipt of a bare-metal stent (15.4% vs 22.1%). The difference was driven by a nearly 50% relative reduction in the risk of target lesion revascularization (7.2% vs 13.1%). The rates of death and MI did not differ between groups.
Take Home Pearls: For patients with coronary artery lesions that develop in saphenous vein grafts following CABG, drug-eluting stents appear to be more effective than bare-metal stents at preventing major adverse events 1 year after stent placement. At 1 year, the rate of all-cause death, MI, or target lesion revascularization appears to be significantly lower in patients who receive drug-eluting stents.
RF Ablation Beneficial for AF Patients [back to top]
The Particulars: Atrial fibrillation (AF) is becoming increasingly common among older patients and is a major risk factor for stroke and transient ischemic attacks (TIAs). Radiofrequency (RF) ablation is an expensive procedure that utilizes many medical resources but may offer advantages to patients. Few studies have explored the efficacy of RF ablation in older patients with AF.
Data Breakdown: A retrospective cohort analysis of 801 matched AF patient pairs was conducted in which patients were propensity-matched on the basis of 15 characteristics, including demographics, comorbid conditions, medication usage, and prior stroke or TIA. The relative risk of stroke events was decreased by 40% among patients who underwent RF ablation when compared with those treated medically. A 37% reduction in heart failure-related events in these AF patients was also observed. Among patients who underwent RF ablation, about 40% were still using medication 3 years later, compared with more than 60% of those who had remained on medical therapy.
Take Home Pearls: Among patients with AF, RF ablation appears to reduce the risk of stroke and TIA and help reduce heart failure events. Patients with AF who underwent RF ablation also appear to have a reduction in medication used to control arrhythmias. More randomized trials may provide more definitive results.
Lung Transplants & Atrial Flutter [back to top]
The Particulars: Atypical atrial flutter appears to occur commonly after lung transplantation in adults, according to clinical studies. However, atrial flutter is most often a self-limited arrhythmia that resolves spontaneously without the need for ablation. Little is known about the incidence of atrial flutter within the lung transplantation population.
Data Breakdown: Researchers reviewed the medical records of 269 consecutive patients who underwent unilateral or bilateral lung transplantation. They identified 35 patients who developed atrial flutter, about 68% of whom had atypical atrial flutter. By 50 days after surgery, atrial flutter disappeared for all patients except in three, in whom the rhythm was persistent and ablative technology was required. Patients who were more likely to experience atrial flutter included those who were of advanced age, those diagnosed with idiopathic pulmonary fibrosis, and those who had left atrial enlargement.
Take Home Pearls: About 13% of patients who undergo lung transplantation procedures appear to develop atrial flutter after their procedure. More research is needed to gain a better understanding of the mechanisms for the incidence of atrial flutter among these patients.
Can Yoga Reduce Atrial Fibrillation Episodes? [back to top]
The Particulars: Paroxysmal atrial fibrillation (AF) has been shown to increase the risk of stroke and may also increase anxiety and reduce quality of life. Systemic stress and inflammation and endothelial dysfunction have been shown to play a role in AF. Yoga has been shown to improve these problems in clinical studies, but little is known about its effect on patients with paroxysmal AF.
Data Breakdown: A study of 49 consecutive paroxysmal AF patients without physical limitations assigned patients to 3 months of regular exercise of the patient’s choice in a control phase, and then 3 months of supervised yoga sessions (60 minutes, twice a week) with encouragement to do yoga on their own on other days of the week. All patients continued medication regimens during the study. Regular-guided yoga sessions with relaxation and breathing exercises reduced the number of AF episodes by nearly 45%, to an average of 2.1 over 3 months, compared with 3.8 doing other types of exercise for 3 months. Anxiety scores and depressive symptoms also decreased among yoga participants. Benefits were also reported in blood pressure and heart rate, both of which contribute to the milieu behind AF attacks.
Take Home Pearls: Regular-guided yoga sessions with relaxation and breathing exercises appear to reduce the number of episodes of AF for paroxysmal patients. Quality of life, depression, and anxiety also improved for AF patients who took part in yoga regimens. Although an inexpensive, noninvasive strategy, yoga should not be viewed as a substitute for medical treatment.
Readings & Resources (click to view)
For more information on these items and other research that was presented at ACC.11 and i2 Summit 2011, go to www.accscientificsession.org.