Heart Beat: April 2018
Drug Combo May Help Prevent Stroke in Patients with Stable Heart Disease
The risk of stroke or heart attack is 5 to 10 percent per year in patients with stable atherosclerosis. Currently, aspirin is the medicine of choice to prevent stroke. Last year, researchers reported the results of a trial designed to determine whether rivaroxaban (Xarelto), or the combination of aspirin and rivaroxaban, might be more effective than aspirin and just as safe. They found that the two-drug combination was better at preventing cardiovascular death, stroke and heart attack than aspirin alone (4.1 percent vs 5.4 percent), but caused a higher rate of major bleeding (3.1 percent vs 1.9 percent). Rivaroxaban alone did not reduce the risk of all types of strokes and nearly tripled the risk of hemorrhagic stroke. The researchers continued to review outcomes data from this trial and at the International Stroke Conference in January 2018 reported that the two-drug combination had been particularly effective in patients with a history of stroke, reducing the rate of a second stroke in this high-risk population from 3.4 percent to 0.7 percent per year. The duo also reduced the risk of strokes that resulted in mild deficits at the time of hospital discharge and strokes that caused severe deficits or death. This makes the combination of aspirin and rivaroxaban a candidate for preventive therapy.
Bariatric Surgery May Lower Cardiovascular Risk from Obesity-Related Diabetes
Obese patients with type 2 diabetes are at greatly increased risk for heart attack and stroke, largely due to elevated blood glucose, blood pressure and cholesterol levels. For some of these patients, Roux-en-Y gastric bypass surgery may be just what they need to lower their cardiovascular risk. In a small study published Jan. 16, 2018, in the Journal of the American Medical Association, researchers reported that within five years after the surgery, 23 percent of the participants had achieved goals set by the American Diabetes Association: hemoglobin A1c less than 7.0 percent, LDL cholesterol less than 100 mg/dL and systolic blood pressure below 130 mmHg. In contrast, only 4 percent of obese patients who chose medical management achieved control over these risk factors. Notably, however, success waned over time. Prior to surgery, the mean HbA1c level in both patient groups was 9.6 percent. Within the first year, 83 percent of patients in the surgical group, but only 29 percent of those being medically managed, achieved an HbA1c of 7.0 percent. By year five, these figures had dropped to 55 percent and 14 percent, respectively. The achievements also came with a higher risk of adverse events from surgery: 66, compared with 38 in the medical group.
New Approach Eliminates Deadly Arrhythmia When Other Treatments Fail
In the first study of its kind, stereotactic external beam radiation, a type of radiation therapy used to treat tumors, proved effective in virtually eliminating ventricular tachycardia (VT) in patients who had failed conventional treatment. In VT, the heart beats rapidly in an uncoordinated fashion, rendering it unable to pump. Unless the heart can be shocked back into a normal rhythm, VT can be fatal. The treatment of choice is often an implantable cardioverter-defibrillator (ICD), which acts as internal shock paddles when it senses the arrhythmia. Patients may also take one or more medications to prevent the arrhythmia and may even undergo radiofrequency catheter ablation to destroy cells in the heart responsible for triggering the arrhythmia. Despite these efforts, a small number of patients continue to experience repeated episodes of VT that cause their ICD to discharge. As reported in the Dec. 13, 2017, New England Journal of Medicine, researchers used external beam radiation to perform ablations on five patients with VT that had failed to respond to other treatments. The painless, noninvasive procedure was completed in 14 to 18 minutes and was nearly 100 percent successful in preventing recurrences of the arrhythmia. In the three months prior to the procedure, the five patients had experienced a total of 6,577 VT episodes. In the six weeks following the procedure, the number of episodes dropped to 680. From this point through the remainder of the first year, only four episodes occurred.