New research was presented at ACC.15, the annual scientific sessions of the American College of Cardiology, from March 14 to 16 in San Diego. The features below highlight some of the studies that emerged from the conference.

CPAP Decreases Acute HF Rehospitalization Rates

The Particulars: Prior research has identified sleep-disordered breathing in heart failure (HF) as a significant risk factor for patients with different forms of HF that can impact clinical outcomes. However, data are lacking on whether compliance with continuous positive airway pressure (CPAP) treatment influences readmission rates among patients with acute HF and sleep apnea.

Data Breakdown: Patients who had been hospitalized for HF and determined to have sleep apnea within 4 weeks of discharge were examined for a study. Among those who were compliant with their CPAP treatment, average pulmonary artery systolic pressure levels decreased, whereas non-compliant patients experienced an increase in these levels. The average number of rehospitalizations decreased by 0.8 visits from baseline to 6 months follow-up in the compliant group but increased by 1.1 visits in the non-compliant group.

Take Home Pearl: Compliance with CPAP therapy appears to reduce 6-month readmission rates among patients with acute decompensated HF who are found to have sleep apnea shortly after being discharged from the hospital.

Sedentary Behavior & Coronary Artery Calcification

The Particulars: Physical activity has been shown to have multiple cardiovascular benefits in numerous studies, but no definitive relationship has been shown between physical activity and coronary artery calcification (CAC). Little is known about the relationship between sedentary behavior and CAC, independent of physical activity.

Data Breakdown: For a study, researchers analyzed data on more than 2,000 patients who did not have any known cardiovascular diseases. No association was observed between moderate-to-vigorous physical activity and CAC. However, a longer amount of time being sedentary was associated with greater CAC. Each hour of sedentary time was associated with a 14% increase in CAC.

Take Home Pearls: Longer periods of sedentary time appear to be associated with CAC, independent of physical activity and traditional cardiovascular risk factors. Additional research is needed to assess whether reducing sedentary time improves the burden of coronary atherosclerosis.

Cancer Risk in MI Survivors

The Particulars: Few studies have assessed the incidence of cancer among myocardial infarction (MI) survivors. Knowledge of any relationship between cancer and MI itself, MI treatment, or both could impact future treatment for patients.

Data Breakdown: Investigators examined records for approximately 126,000 MI survivors with a history of cancer and more than 3 million MI survivors without a history of MI or cancer. After up to 17 years of follow-up, MI survivors had an incidence rate for any cancer of 173.5 per 10,000 person-years, compared with a rate of 85.2 per 10,000 person years for controls. The highest relative risks for developing cancer were seen during the first month following MI, and rates of cancer were highest among those aged 30 to 54. The authors noted that patients with a previous MI were at higher risk for lung and bladder cancer.

Take Home Pearls: Survivors of MI appear to be at higher risk for developing cancer—particularly lung and bladder cancer—when compared with the general population. Future research is warranted to determine if smoking, cardiac medications, or other factors play a role in increasing this risk.

Prolonging Heart Failure-Free Survival

The Particulars: Evidence suggests that quantifying heart failure-free survival in the context of risk factor burden in mid-life may improve risk communication and prevention efforts. Study results to confirm this hypothesis are lacking.

Data Breakdown: Northwestern University researchers performed survival analyses on participants from several large studies who were free from cardiovascular disease at baseline. Men and women without hypertension, obesity, or diabetes lived an average of 35.3 and 37.0 years, respectively, without incident heart failure. Patients with hypertension, obesity, diabetes, or any combination of these conditions at baseline had heart failure-free survival that was 3 to 11 years shorter than those with none of these diseases. Patients without hypertension, obesity, or diabetes at age 45 lived an average of 11.3 to 12.7 years longer free of hypertension than those with all three factors.

Take Home Pearl: Reducing hypertension, obesity, and diabetes prevalence by age 45 appears to substantially prolong heart failure-free survival.

The Role of Gender in STEMI Outcomes

The Particulars: Gender-related factors associated with ST-segment elevation myocardial infarction (STEMI) outcomes have not been well defined in clinical research. Investigating sex-related differences in access to care among patients with STEMI may help identify factors that can improve outcomes.

Data Breakdown: For a study, Italian investigators measured multiple outcomes in nearly 7,500 STEMI patients. Women were less likely than men to receive care within 12 hours of symptom onset and were therefore less likely to undergo reperfusion therapy with either primary PCI or fibrinolysis. Women also had longer time delays to call EMS. Home-to-hospital delays of 60 minutes or longer occurred in more than 70% of women, compared to a rate of less than 30% that was observed in men. Women had greater in-hospital mortality rates than men. However, this difference was no longer observed when time to treatment from symptom onset of 12 hours or more was included in the multivariable analysis.

Take Home Pearls: Gender differences appear to be prevalent among STEMI patients with regard to timeliness of care and outcomes. Pre-hospital delays in women with STEMI appear to be particularly long.

Surgical Ablation of AF During Mitral-Valve Surgery

The Particulars: Prior studies indicate that 30% to 50% of patients undergoing mitral-valve surgery present with atrial fibrillation (AF). Surgical ablation of AF is widely used, but data regarding its safety and effectiveness are limited.

Data Breakdown: For a study, patients with AF who required mitral-valve surgery were randomized to surgical ablation or no ablation (control) during their surgery. At both 6 and 12 months, more patients in the ablation group were free from AF than in the control group (63% vs 29%). The 1-year mortality rates were 6.8% for the ablation group and 8.7% for the control group. However, ablation was associated with more implantations of a permanent pacemaker than no ablation.

Take Home Pearls: Adding surgical ablation to mitral-valve operations appears to significantly increase the rate of freedom from AF at 1 year among patients with AF. However, the risk of needing a permanent pacemaker to be implanted is higher with the addition of surgical ablation when compared with no ablation.

TAVR Vs SAVR in High-Risk Patients

The Particulars: Previous research has suggested that 1-, 2-, and 3-year mortality rates are similar with transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) for high-risk patients with aortic stenosis. Information on 4-year outcomes following SAVR and TAVR in this patient population may help determine any relative differences in benefits between the two procedures.

Data Breakdown: About 700 high-risk patients with severe aortic stenosis were randomized to SAVR or TAVR for a study and followed for at least 5 years. At 4 years, the all-cause mortality rates were about 55% for both groups and cardiac death rates were about 39% for both groups. The frequency of all strokes during follow-up also did not differ significantly, registering at about 10% for both groups. Among survivors at 4 years, 87% of SAVR patients and 84% of TAVR patients were in New York Heart Association classes I and II.

Take Home Pearls: Among high-risk patients, 4-year follow-up data appear to support TAVR as an alternative to SAVR. Both TAVR and SAVR had similar mortality rates and functional outcomes.

TAVR Vs SAVR in High-Risk Patients

The Particulars: Previous research has suggested that 1-, 2-, and 3-year mortality rates are similar with transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) for high-risk patients with aortic stenosis. Information on 4-year outcomes following SAVR and TAVR in this patient population may help determine any relative differences in benefits between the two procedures.

Data Breakdown: About 700 high-risk patients with severe aortic stenosis were randomized to SAVR or TAVR for a study and followed for at least 5 years. At 4 years, the all-cause mortality rates were about 55% for both groups and cardiac death rates were about 39% for both groups. The frequency of all strokes during follow-up also did not differ significantly, registering at about 10% for both groups. Among survivors at 4 years, 87% of SAVR patients and 84% of TAVR patients were in New York Heart Association classes I and II.

Take Home Pearls: Among high-risk patients, 4-year follow-up data appear to support TAVR as an alternative to SAVR. Both TAVR and SAVR had similar mortality rates and functional outcomes.

Remote Ischemic Preconditioning in CABG Patients

The Particulars: Remote ischemic preconditioning (RIPC)—a procedure in which cycles of brief ischemia/reperfusion are applied to the arm—has been shown in previous reports to reduce the extent of perioperative myocardial infarction in patients undergoing CABG. Whether RIPC improves long-term clinical outcomes in this patient population remains unknown.

Data Breakdown: For a study, British investigators assessed the effect of RIPC on major adverse cardiac and cerebral events at 12 months in patients under­going on-pump CABG. Participants were randomized to receive RIPC or simulated RIPC (control group). At 1 year, 26.6% of patients in the RIPC group experienced cardiovascular death, non-fatal heart attack, stroke, or subsequent surgery or angioplasty, compared with a rate of 27.7% that was observed for the control group. However, the risk of heart injury within the first 72 hours of surgery was 15.0% lower for the RIPC group when compared with the control group.

Take Home Pearl: RIPC does not appear to improve long-term health outcomes in patients under­going CABG when compared with no RIPC but may be beneficial in other settings of acute ischemia or reperfusion injury.

A Promising TAVR System

The Particulars: The Sapien 3 transcatheter aortic valve replacement (TAVR) system (Edwards Lifesciences Corp.) is a balloon-expandable valve with an external fabric skirt that may help minimize paravalvular regurgitation (PVR). Evaluations of the system’s performance are lacking.

Data Breakdown: More than 1,500 patients with aortic stenosis who participated in a study underwent TAVR using the Sapien 3 system. In high-risk patients, the 30-day all-cause mortality rate was 2.2% and the cardiac mortality rate was 1.4%. Other complication rates included:

♦  1.6% for all strokes.
♦  0.5% for myocardial infarction.
♦  5.0% for major vascular complications.
♦  13.1% for requirement of a permanent pacemaker.

About two-thirds of patients had no PVR or only a trace of PVR after receiving the TAVR system. PVR was mild in 35.5% of cases, but moderate in 2.9% of cases and was not severe in any case.

Take Home Pearl: The Sapien 3 TAVR system appears to have low short-term risk of complications and reduces PVR when compared with clinical studies assessing other transcatheter valves.