Heart Beat: September 2018
Smartphone App Helps Patients with Diabetes Manage Their Insulin
Patients with type 1 diabetes require multiple insulin injections a day. This can make it difficult to keep blood glucose levels within the ideal range. Now there’s a smartphone app that can help. The Guardian Connect continuous glucose monitoring system works hand-in-hand with the Sugar:IQ app to analyze how patients’ glucose levels are responding in real time to food intake, insulin and other variables. Data are sent to the cloud for processing, and the information is returned to the app for viewing on an iPhone. The system helps patients identify foods and habits that cause their glucose to spike, as well as times of the day or week when glucose levels fluctuate. This allows them to adjust their insulin use accordingly. In a pilot study, patients using the system spent 33 minutes more per day in the ideal glucose range and had one less hyperglycemic event per month. When the Sugar:IQ app explained the dangers of hypoglycemia, the number of hypoglycemic events dropped in more than half of app users. The system, which has been approved by the U.S. Food and Drug Administration (FDA), is now being retooled for Android users.
New Heart-Failure Therapy Serves Patients without Other Choices
A new type of treatment called cardiac contractility modulation (CCM) appears to improve heart function in heart-failure patients with few other options. Such patients typically have NYHA class III heart failure despite optimal medical therapy, but are not sick enough for a left ventricular assist device or heart transplant and do not qualify for cardiac resynchronization therapy (CRT). These “gap” patients may qualify for the Optimizer, an implantable system consisting of a pulse generator and leads. In CCM, the pulse generator stimulates the heart’s electrical system in specified intervals throughout the day. Unlike a pacemaker, however, CCM does not affect the heart’s rhythm. Rather, heart function improves first at the stimulation site, then later throughout the heart. As published ahead of print May 10, 2018, in JACC: Heart Failure, patients who received the Optimizer realized significant improvements in exercise capacity and 6-minute walk test. They reported fewer heart-failure symptoms and hospitalizations, enjoyed a better quality of life and lived longer than peers who did not receive CCM. In the 24-week study, twice as many patients on CCM improved at least one NYHA class—a response generally seen with CRT. The Optimizer device has been submitted to the FDA for approval.
Treating Obstructive Sleep Apnea Fails to Improve Cardiovascular Health
Obstructive sleep apnea (OSA), a disorder that causes sleepers to briefly stop breathing hundreds of times a night, is associated with increased risk of cardiovascular disease. The low levels of oxygen and high levels of carbon dioxide in the blood resulting from these apneas elevate blood pressure and cause arrhythmias. OSA doubles the risk of sudden cardiac death and increases the risk of a fatal or nonfatal heart attack by 30 percent. So it stands to reason that the use of continuous positive airway pressure (CPAP) to prevent apneas should lower the risk of cardiovascular events, but apparently, it does not. A review of 10 randomized clinical trials involving more than 7,000 patients published ahead of print July 11, 2018, in the Journal of the American Medical Association found that CPAP was not associated with a reduction in major adverse cardiovascular events, cardiovascular death, all-cause death, stroke or heart failure, compared with no treatment. The finding follows a prospective clinical trial by the same researchers in which 2,717 participants with OSA and cardiovascular or cerebrovascular disease were randomized to CPAP plus usual care or usual care alone. In this trial, published Sept 8, 2016, in the New England Journal of Medicine, no significant difference was seen in the rate of cardiovascular events, death from cardiovascular causes, heart attack, stroke or hospitalization for unstable angina, heart failure or transient ischemic attack when CPAP was provided. These findings do not diminish the value of CPAP in helping eliminate daytime sleepiness. The treatment also can improve blood pressure, blood sugar control, memory and depression. What it does suggest is that patients with OSA should be evaluated for cardiovascular risk factors and treated appropriately.