The hottest research from various peer-reviewed journals – handpicked weekly by the ACC.org Editorial Board led by Kim A. Eagle, MD, MACC.
No Differences in Lead Failure in Most Common ICD Leads: NCDR StudyAmong the four most common ICD leads, there are no clinically significant differences in high-energy lead failure, according to a study published in Circulation: Cardiovascular Quality and Outcomes.
In a post-market surveillance study, Frederic S. Resnic, MD, MSc, FACC, et al., used data from ACC's ICD Registry to assess the comparative long-term safety of the four most commonly used ICD leads. The study's primary safety outcome was survival without lead failure for any reason, based on ICD Registry records of a subsequent procedure to remove and/or replace the original lead.
The secondary outcome was late lead survival, which included only patients who did not experience lead failure within the first 30 days following ICD implantation. For each of the four ICD leads, a propensity-matched control population consisting of patients treated with any of the other leads was identified to create device-specific comparisons.
A total of 374,132 patients received one of the four ICD leads of interest. Patients had a mean age of 65 years, 39% had diabetes and 29% were female. About 58% of patients had ischemic cardiomyopathy and 78% received the ICD for primary prevention of sudden death.
Results showed that of identified lead failures, 44% occurred within 30 days of ICD implantation.
After five years of surveillance, there were no safety alerts for lead failure for any of the four leads. In addition, after five years, freedom from lead replacement ranged from 97.7% to 98.9% for each of the four high-energy leads.
There were no differences in freedom of lead replacement among different patient cohorts, including women, patients younger or older than 60 years, those who received the ICD for primary or secondary prevention, or patients with diabetes or end-stage renal disease.
The study's findings "support the feasibility of prospective, active surveillance of a large, representative ICD Registry to monitor high-energy lead failure in near real time," write the authors.
The study "is a great step towards repurposing clinical data for public health and safety," Emily P. Zeitler, MD, MHS, FACC, and Kimberly A. Selzman, MD, MPH, FACC, write in an accompanying editorial. The set of surveillance software tools developed for the analysis "serve as a path forward for repurposing existing data systems to serve the medical device ecosystem and public health at large," they conclude.
Resnic FS, Majithia A, Dhruva SS, et al. Circ Cardiovasc Qual Outcomes 2020 Apr;13(4):e006105.
Women, Older Adults Inadequately Represented in Lipid-Lowering Trials
A systematic review of randomized clinical trials (RCTs) of lipid-lowering therapies (LLTs) found women and older adults are consistently underrepresented, despite ongoing efforts to increase inclusion of these populations, found a study published in JAMA Network Open.
For this analysis, researchers selected primary and secondary prevention studies of LLTs with at least 1,000 participants conducted between 1990 and 2019 with follow-up of at least one year. In total, 60 trials with 485,409 participants were included, to examine the prevalence of women and older (age >65 years) participants, temporal trends in participation, representations of women in RCTs relative to disease burden (using the participation-to-prevalence ratio [PPR] metric), and trends in reporting outcomes based sex and age.
Looking at women, representation overall was 28.5%, increasing from 19.5% for the period of 1990 to 1994 to 33.6% for the period of 2015 to 2018. Some common factors limiting the representation of women in RCTs was the inclusion of only postmenopausal women or surgically sterile women and the exclusion of pregnant and lactating women.
Compared with their disease burden, women were underrepresented in lipid RCTs of diabetes (PPR, 0.74); heart failure (PPR, 0.27); stable coronary heart disease (PPR, 0.48); and acute coronary syndrome (PPR, 0.51).
Regarding older adults, only 23 RCTs with 263,628 participants reported the proportion of older participants. Their overall representation was 46.7%, a numerical increase from 31.6% to 46.2% for the periods of 1995 to 1998 and 2015 to 2018.
Only 53% of trials reported outcomes according to sex and only 36.6% according to older adults, with no improvement found over time.
Noting there was only modest improvement in enrollment over time, likely reflective of regulations by the U.S. Food and Drug Administration, they add there are no legal or regulatory mandates requiring a specific proportion of participants based on sex or age.
"Therefore, practical steps should be undertaken to develop new strategies to achieve optimal recruitment of these subsets of the population in RCTs, and investigators should be encouraged to report results based on these subgroups to enhance generalizability of their results," the authors write.
Khan SU, Khan MZ, Subramanian CR, et al. JAMA Netw Open 2020;3(5):e205202.
Low Rate of Secondary Prevention Treatment in Most MI Patients
Patients with a prior myocardial infarction (MI) and elevated LDL-C levels are at a particularly high risk for recurrent ischemic events and need to be targeted with aggressive medical therapy over time to maximize survival and quality of life. Yet a new analysis found only about a third were receiving optimal medical therapy, according to a research letter published in JAMA Network Open.
Suzanne V. Arnold, MD, MHA, et al., examind the postdischarge use of evidence-based therapies for secondary prevention in GOULD, a large contemporary cohort of U.S. patients with prior MI and elevated LDL-C. Prior research has shown that secondary prevention medication prescription rates are high at discharge, but the intensity of preventive therapies tends to decrease over time because of clinical decisions and patient nonpersistence.
Researchers examined data from 1,564 patients with atherosclerotic cardiovascular disease and prior MI. The median age was 67 years, 1,055 (67.5% were men), 589 (37.7%) had diabetes and the median LDL-C level was 90 mg/dL.
Results showed that among the participants, 1,361 (87%) were taking a statin, 758 (48.5%) a high-intensity statin and 1,475 (94.3%) were taking an antiplatelet agent or anticoagulant. Of the 259 patients with an MI within the previous year, 177 (68.3%) were on dual antiplatelet therapy, 160 (61.8%) were taking a high-intensity statin, 211 (81.5%) a beta-blocker and 164 (3.3%) were taking an ACEI or ARB.
Notably, only 571 (36.5%) of the study participants were receiving optimal medical therapy for secondary prevention.
"Persistence with each of these classes of medications substantially reduces recurrent ischemic events, heart failure and cardiovascular mortality," the authors write. "As such, ensuring patients with a prior MI and elevated LDL cholesterol levels, who represent some of the highest risk patients, are receiving consistent and aggressive secondary prevention therapy over time (and not just at hospital discharge) must be a priority."
Arnold SV, de Lemos JA, Liu Y, et al. JAMA Netw Open 2020;Apr;3(4):e203032.
Keywords: ACC Publications, Cardiology Magazine, Secondary Prevention, Prevalence, Follow-Up Studies, Registries, Medical Records, Outcome Assessment (Health Care), Longitudinal Studies, Lipids
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