Pulmonary vein isolation plus adjunctive therapy for the treatment of atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

Pulmonary vein isolation (PVI) is the primary technique for ablation of atrial fibrillation (AF). It is unclear whether adjunctive therapies in addition to PVI can reduce atrial arrhythmia recurrence (AAR) compared to PVI alone in patients with AF.

METHODS

A meta-analysis of randomized controlled trials comparing PVI plus an adjunctive therapy (autonomic modulation, linear ablation, non-pulmonary vein trigger ablation, epicardial PVI [hybrid ablation], or left atrial substrate modification) to PVI alone was conducted. The primary outcome was AAR. Cumulative odd's ratios (OR) and 95% confidence intervals (CI) were calculated for each treatment type.

RESULTS

Forty-six trials were identified that included 8,500 participants. The mean age (± standard deviation) was 60.2 (±4.1) years, and 27.2% of all patients were female. The mean follow-up time was 14.6 months. PVI plus autonomic modulation and PVI plus hybrid ablation were associated with a relative 53.1% (OR 0.47; 95% CI 0.32 to 0.69; p < 0.001) and 59.1% (OR 0.41; 95% CI 0.23 to 0.75; p = 0.003) reduction in AAR, respectively, compared to PVI alone. All categories had at least moderate interstudy heterogeneity except for hybrid ablation.

CONCLUSION

Adjunctive autonomic modulation and epicardial PVI may improve the effectiveness of PVI. Larger, multi-center randomized controlled trials are needed to evaluate the efficacy of these therapies.

Re-Analyses of 8 Historical Trials in Cardiovascular Medicine Assessing Multimorbidity Burden and Its Association with Treatment Response

OBJECTIVE

The purpose of this study was to examine the multimorbidity burden of clinical trial participants and assess its association with treatment response.

METHODS

We conducted a reanalysis of patient level data. There were 29,954 participants from 8 clinical trials containing 11 comparisons between an intervention and control condition. Patients were classified by Charlson Comorbidity Index (CCI) score. The primary outcomes were the primary study endpoints as originally specified for each trial. A Cox model that included the CCI score groups, the randomized group, and their interaction, was used to compare the primary outcome between randomized groups. The interaction term between randomized group and comorbidity index allowed the treatment effect to differ by level of comorbidity index and comprised the primary effect of interest. Hazard ratios and risk differences were reported for all comparisons.

RESULTS

The mean CCI scores of trial populations ranged from 2.1 to 3.9 points, and the percentage of patients with scores ≥5 from 3% to 39%. Tests of interaction terms in models yielded P values ≤ .10 for 4/11 comparisons and ≤ .05 for 2/11 comparisons. In 3 additional comparisons, potentially important treatment variation on an absolute scale was observed despite interaction tests with P values > .10 on the relative scale.

CONCLUSIONS

These trials were mainly composed of patient populations with CCI scores ≤4. Despite this, biologically plausible treatment interactions were commonly suggested. These results are hypothesis generating; confirmation of results would require larger studies or studies targeted specifically toward patients with higher levels of multimorbidity.

Non-pharmacologic autonomic neuromodulation for treatment of heart failure: A systematic review and meta-analysis of randomized controlled trials

Treatment strategies that modulate autonomic tone through interventional and device-based therapies have been studied as an adjunct to pharmacological treatment of heart failure with reduced ejection fraction (HFrEF). The main objective of this study was to perform a meta-analysis of randomized controlled trials which evaluated the efficacy of device-based autonomic modulation for treatment of HFrEF. All randomized-controlled trials testing autonomic neuromodulation device therapy in HFrEF were included in this trial-level analysis. Autonomic neuromodulation techniques included vagal nerve stimulation (VNS), baroreflex activation (BRA), spinal cord stimulator (SCS), and renal denervation (RD). The prespecified primary endpoints included mean change and 95% confidence intervals (CI) of left ventricular ejection fraction (LVEF), NT pro-B-type natriuretic peptide (NT-proBNP), and quality of life (QOL) measures including 6-minute hall walk distance (6-MHWD), and Minnesota Living with Heart Failure Questionnaire (MLHFQ). New York Heart Association (NYHA) functional class improvement was reported as odds ratios and 95% CI of improvement by at least 1 functional class. Eight studies were identified that included 1037 participants (2 VNS, 2 BRA, 1 SCS, and 3 RD trials). This included 6 open-label, 1 single-blind, and 1 sham-controlled, double-blind study. The mean age (±SD) was 61 (±9.3) years. The mean follow-up time was 7.9 months. Twenty percent of the total patients were female, and the mean BMI (±SD) was 29.86 (±4.12). Autonomic neuromodulation device therapy showed a statistically significant improvement in LVEF (4.02%; 95% CI 0.24,7.79), NT-proBNP (-219.80 pg/ml; 95% CI -386.56, -53.03), NYHA functional class (OR 2.32; 95% CI 1.76, 3.07), 6-MHWD (48.39 m; 95% CI 35.49, 61.30), and MLHFQ (-12.20; 95% CI -19.24, -5.16) compared to control. In patients with HFrEF, the use of autonomic neuromodulation device therapy is associated with improvement in LVEF, reduction in NT-proBNP, and improvement in patient-centered QOL outcomes in mostly small open-label trials. Large, double-blind, sham-controlled trials designed to detect differences in hard cardiovascular outcomes are needed before widespread use and adoption of autonomic neuromodulation device therapies in HFrEF.

Menopausal hormone therapy and coronary heart disease: the roller-coaster history

In the USA it is estimated that more than one million women become menopausal each year. Coronary heart disease (CHD) is the leading cause of mortality in menopausal woman globally. The majority of perimenopausal to postmenopausal women experience bothersome symptoms including hot flashes, night sweats, mood liability, sleep disturbances, irregular bleeding and sexual dysfunction. While menopausal hormone therapy (HT) effectively treats most of these symptoms, use of HT has become confusing, especially related to CHD risk. Despite years of observational and retrospective studies supporting a CHD benefit and improved survival among HT users, the Heart and Estrogen/Progestin Replacement Study (HERS) and the Women's Health Initiative (WHI) raised doubts about this long-held premise. The timing hypothesis has since emerged and states that when HT is initiated in younger women, soon after menopause onset, there may be cardiovascular benefit. The following review discusses the roller-coaster history of HT use as it pertains to CHD in postmenopausal women. Studies that highlight HT's CHD benefit are reviewed and provide reassurance that HT utilized in appropriately selected younger postmenopausal women close to the onset of menopause is safe from a cardiovascular perspective, in line with consensus recommendations.

A systematic review, meta-analysis, and meta regression of the sham controlled renal denervation randomized controlled trials

Renal denervation (RD) has been investigated as a novel blood pressure (BP) lowering treatment for hypertension. The primary objective of this meta-analysis was to assess the efficacy of RD and factors that may associate with treatment effect heterogeneity. The primary outcomes were raw mean differences (RMD) in 24-hour ambulatory, daytime ambulatory, nighttime, and office systolic BP (SBP) and diastolic BP (DBP) between sham control and RD. A prespecified subgroup analysis was performed comparing studies with follow-up less than versus greater than 4 months. If inter-study heterogeneity was found for any of the above outcomes, additional analyses were performed to assess potential moderator variables. Ten sham-controlled randomized trials were identified and included 1,544 participants, followed for a mean of 4.20 months. RD was associated with a statistically significant reduction in all SBP and DBP measures except for nighttime SBP (-2.64 mmHg; 95% confidence interval (CI) -5.84 to 0.56, p = 0.11) and nighttime DBP (- 1.21 mmHg; 95% CI -3.17 to 0.75, p = 0.23). Mild to moderate inter-study heterogeneity was identified for three outcomes (office SBP and nighttime SBP and DBP). Studies that followed patients for longer than 4 months had numerically lower reductions in most BP outcomes; however, there were no statistically significant interactions between subgroups. Compared to a sham procedure, RD was associated with statistically significant reductions in most measures of SBP and DBP that were within bounds of what would be expected from standard blood pressure lowering medications.

Association between diseases of despair and atherosclerotic cardiovascular disease among insured adults in the USA: a retrospective cohort study from 2017 to 2021

OBJECTIVES

To assess associations between diseases of despair (DoD) and incident atherosclerotic cardiovascular disease (ASCVD) among insured adults in the USA.

DESIGN

Retrospective cohort study.

SETTING

Highmark insurance claims data in the USA from 2017 to 2021.

PARTICIPANTS

Adults with at least 10 months of continuous insurance enrolment, no record of ASCVD in the 2016 baseline year and no missing data on study variables.

PRIMARY AND SECONDARY OUTCOME MEASURES

Cox proportional hazard regression was used to calculate crude and adjusted hazard ratios (HR) and 95% confidence intervals (CI) to assess risk of ASCVD (composite of ischaemic cardiomyopathy, non-fatal ischaemic stroke, peripheral arterial disease or non-fatal acute myocardial infarction) by baseline DoD overall, and by the component conditions comprising DoD (alcohol-related disorders, substance-related disorders, suicidality) individually and in combination.

RESULTS

The DoD-exposed group had an age-adjusted rate of 20.5 ASCVD events per 1000 person-years, compared with 11.7 among the unexposed. In adjusted models, overall DoD was associated with increased risk of incident ASCVD (HR 1.42, 95% CI 1.36 to 1.47). Individually and in combination, component conditions of DoD were associated with higher risk for ASCVD relative to no DoD. Substance-related disorders were associated with 50% higher risk of incident ASCVD (HR 1.5, 95% CI 1.41 to 1.59), alcohol-related disorders and suicidality/intentional self-harm were associated with 33% and 30% higher risk, respectively (HR 1.33, 95% CI 1.26 to 1.41; HR 1.30, 95% CI 1.11 to 1.52). Co-occurring DoD components conferred higher risk still. The highest risk combination was substance-related disorders+suicidality (HR 2.01, 95% CI 1.44 to 2.82).

CONCLUSIONS

Among this cohort of insured adults, documented DoD was associated with increased ASCVD risk. Further research to understand and address cardiovascular disease prevention in those with DoD could reduce costs, morbidity and mortality. Further examination of overlapping structural factors that may be contributing to concurrent rises in ASCVD and DoD in the USA is needed.

A systematic review and meta-analysis of all sham and placebo controlled trials for resistant hypertension

INTRODUCTION

There is a lack of consensus regarding the best add on therapy for treatment of resistant hypertension (RH). This is likely secondary to a paucity of data on the comparative effectiveness of proposed therapies for RH.

METHODS

Placebo-controlled and sham-controlled randomized clinical trials testing therapies for the treatment of RH were included in this meta-analysis. Therapies with two or more studies were included as subgroups in this meta-analysis. The primary outcomes being tested were 24-hr systolic blood pressure (SBP) and office SBP.

RESULTS

Eight studies were identified that tested mineralocorticoid receptor antagonist (MRA) including 1,414 participants. The raw mean difference (RMD) between MRA and placebo control was statistically significant for 24-hour SBP (-10.56 mmHg; 95% confidence interval (CI) -12.82 to -8.30), 24-hour diastolic (DBP) (-5.48 mmHg; 95% CI -8.48 to -2.58), office SBP (-11.97 mmHg; 95% CI -16.41 to -7.54), and office DBP (-4.14 mmHg; 95% CI -5.62 to -2.65). Six studies were identified that tested renal denervation (RD) including 989 participants. The RMD between RD and sham control was not statistically significant for 24-hour SBP (-1.84 mmHg; 95% CI -3.92 to 0.24), 24-hour DBP (-0.66 mmHg; 95% CI -1.85 to 0.54), office SBP (-1.57 mmHg; 95% CI -6.04 to 2.89), and office DBP (-1.49 mmHg; 95% CI -3.52 to 0.55). Four studies were identified that tested endothelin receptor antagonists (ERA) including 1,193 participants. The raw mean difference (RMD) between ERA and placebo control was statistically significant for 24-hr systolic (SBP) (-7.02 mmHg; 95% CI -9.15 to -4.90, 24-hr diastolic (DBP) (-6.22 mmHg; 95% CI -7.61 to -4.82), office SBP (-5.84 mmHg; 95% CI -10.08 to -1.60), and office DBP (-3.73 mmHg; 95% CI -5.87 to -1.59).

DISCUSSION

MRA lowers BP in patients with RH more than RD, which seems to have little to no effect in RH. ERAs lead to a statistically significant reduction in BP but the confidence in efficacy is limited due to the low number of studies and differences in trial population. Individual factors and their impact on treatment response in RH should be investigated in future research.

Cardiovascular assessment in cirrhosis: is global longitudinal strain altered in cirrhosis? A meta-analysis and review

BACKGROUND AND AIMS

Evaluation of cardiac function and determining the potential risk of cardiac complications with liver transplantation has been both a topic of contention and discussion. Global longitudinal strain (GLS) imaging has been used to identify subclinical myocardial dysfunction in other pathologies; however, its use in the cirrhosis population is unclear. A meta-analysis was performed to assess GLS values in patients with cirrhosis compared to healthy controls.

METHODS

A literature search was conducted for studies that evaluated GLS in patients with cirrhosis compared to healthy controls published until September 18, 2020. Primary outcomes looked at differences in GLS values between these populations.

RESULTS

Thirteen total studies were included in the meta-analysis. Overall, 802 patients with cirrhosis and 540 healthy controls were included in the analysis. The GLS values were numerically more negative in the healthy control group versus patients with cirrhosis (raw mean difference -2.5%, 95% CI -3 to -1.9, P = < .001), I²  = 81%.

CONCLUSION

GLS can be used as an early marker of subclinical myocardial dysfunction. We noted a difference in GLS values in patients with cirrhosis compared to healthy control subjects in this meta-analysis. Other traditional systolic and diastolic echocardiographic parameters were not found to be significantly different between patients with cirrhosis versus healthy controls. This may indicate utilization of GLS when screening for cardiac dysfunction prior to liver transplantation.

A Subgroup Meta-Analysis Comparing the Renal Denervation Sham-Controlled Randomized Trials Among Those With Resistant and Nonresistant Hypertension

Renal denervation (RD) has been investigated as an invasive blood pressure (BP) lowering treatment for hypertension (HTN). Resistant HTN (RHTN) has been defined as uncontrolled BP despite use of 3 antihypertensive medications of different classes, including a diuretic, at maximum tolerated doses. The impact of RD on RHTN remains under investigation. Ten sham-controlled trials testing RD were included in this trial-level analysis. A prespecified subgroup analysis was conducted to test whether efficacy of RD differed in patients with and without RHTN. The primary end points were change in 24-hour ambulatory systolic (SBP) and diastolic (DBP) using raw mean difference (RMD) between sham control and RD. Ten studies (6 RHTN and 4 nonresistant HTN) were identified that included 1,544 participants (1,001 RHTN and 543 essential HTN) with cumulative mean age (±SD) of 57 years (±3). Cochran risk of bias assessment showed 69% of the domains to be at low risk of bias. The RMD for 24-hour SBP between RD and sham control was statistically significant for nonresistant HTN trials (-4.19 mm Hg; 95% confidence interval [CI] -6.07 to -2.30) but was not statistically significant for RHTN trials (-1.86 mm Hg; 95% CI - 3.89 to 0.16). Despite the numerical difference in the subgroups, the interaction between subgroups failed to reach statistical significance (p = 0.10). The RMD for 24-hour DBP between RD and sham control was statistically significant for nonresistant HTN trials (-2.60 mm Hg; 95% CI -3.79 to -1.42) but was not statistically significant for RHTN trials (-0.67 mm Hg; 95% CI -1.84 to 0.50). The interaction between subgroups was statistically significant (p = 0.02). Our analysis indicates RD is a less effective intervention for patients with RHTN. These data may be beneficial for clinicians to consider when assessing patients with RHTN for RD.

Pulmonary vein isolation with adjunctive left atrial ganglionic plexus ablation for treatment of atrial fibrillation: a meta-analysis of randomized controlled trials

BACKGROUND

Adjunctive ganglionic plexus (GP) ablation may increase the efficacy of pulmonary vein isolation (PVI) for treatment of atrial fibrillation (AF). Prior meta-analyses examining PVI with adjunctive GP ablation have included non-randomized trials and have included trials evaluating thorascopic epicardial ablation. The objective of this study is to perform a meta-analysis of randomized controlled trials (RCTs) comparing endocardial catheter-based PVI to PVI with adjunctive GP ablation.

METHODS

Summary odds ratio (OR) and 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed with I² values. Sub-group analysis was performed comparing arrhythmia recurrence between patients with paroxysmal versus persistent AF at trial baseline. Meta-regressions were performed with mean left atrial diameter and left ventricular ejection fraction at trial baseline as the moderator variables.

RESULTS

Five RCTs were identified including 814 patients: 406 PVI + GP ablation and 408 PVI alone. The mean age of participants was 56.5 years and 74.7% were male. Four of these trials evaluated catheter-based endocardial ablation for a total of 574 patients: 289 PVI + GP ablation and 285 PVI alone. The odds of arrhythmia recurrence in patients undergoing adjunctive GP ablation with PVI compared with PVI alone were a reduced: odds ratio (OR) 0.58, 95% confidence interval (CI) 0.41-0.82, I² = 40.2%. In the subgroup analysis, the odds of arrhythmia recurrence with adjunctive GP ablation were reduced in those with paroxysmal AF (OR 0.396, 95% CI 0.23-0.69, I² = 0%). A non-significant trend to reduced arrhythmia recurrence was also observed in those with persistent AF (OR 0.726, 95% CI 0.475-1.112, I² = 0%). When performing the meta-regression, increased left atrial diameter was associated with decreased treatment effect of adjunctive GP ablation (R² index = 1.0, I² = 0%).

CONCLUSIONS

The addition of GP ablation to PVI was associated with reduced arrhythmia recurrence. Adjunctive GP ablation was more effective in paroxysmal AF and in patients with smaller atria. Larger RCTs are needed to confirm the efficacy of GP + PVI ablation.

The association between incidentally found breast arterial calcification on routine screening mammography and the development of coronary artery disease and stroke: results of a 10-year prospective study

OBJECTIVE

The objective of this study is to assess whether the presence of breast arterial calcifications (BACs) found on routine mammography is prospectively associated with the development of cardiovascular disease (CVD) events after 10 years of follow-up.

METHODS

Women presenting for screening mammography were enrolled in this prospective cohort. Baseline data were collected including history of CVD and CVD risk factors. Mammograms were assessed for the presence or absence of BAC. Participants completed questionnaires 10 years after baseline that assessed the development of CVD (coronary artery disease [CAD] and stroke) and CVD risk factors.

RESULTS

Of the 1,995 participants who enrolled at baseline, complete 10-year follow-up data were available for 1,039; of those, 114 (11.0%) were BAC-positive and 925 (89.0%) were BAC-negative at baseline. After controlling for age, BAC-positive women were more likely to develop CAD (odds ratio, 3.14; 95% confidence interval, 1.86-5.27; P < 0.001) compared with BAC-negative women after 10 years of follow-up. After controlling for age, BAC-positive women were more likely to have had a stroke (odds ratio, 5.10; 95% CI, 1.82-14.30) compared with BAC-negative women after 10 years.

CONCLUSIONS

The presence of BAC on routine screening mammography was associated with a significantly increased risk of developing CAD and stroke after 10 years of follow-up. Additional large prospective, population-based studies are needed to confirm BAC as a predictor of future CVD events and its utility in stratifying a woman's risk of CVD.

The severity of individual menopausal symptoms, cardiovascular disease, and all-cause mortality in the Women's Health Initiative Observational Cohort

OBJECTIVE

The aim of this study was to examine the association between common menopausal symptoms (MS) and long-term cardiovascular disease (CVD) and all-cause mortality.

METHODS

In an observational cohort of 80,278 postmenopausal women with no known CVD at baseline from the Women's Health Initiative, we assessed individual MS severity (mild vs none; moderate/severe vs none) for night sweats, hot flashes, waking up several times at night, joint pain or stiffness, headaches or migraines, vaginal or genital dryness, heart racing or skipping beats, breast tenderness, dizziness, tremors (shakes), feeling tired, forgetfulness, mood swings, restless or fidgety, and difficulty concentrating. Outcomes included total CVD events (primary) and all-cause mortality (secondary). Associations between specific MS, their severity, and outcomes were assessed during a median of 8.2 years of follow-up. All results were multivariable adjusted, and individual associations were Bonferroni corrected to adjust for multiple comparisons. A machine learning approach (least absolute shrinkage and selection operator) was used to select the most parsimonious set of MS most predictive of CVD and all-cause mortality.

RESULTS

The severity of night sweats, waking up several times at night, joint pain or stiffness, heart racing or skipping beats, dizziness, feeling tired, forgetfulness, mood swings, restless or fidgety, and difficulty concentrating were each significantly associated with total CVD. The largest hazard ratio (HR) for total CVD was found for moderate or severe heart racing or skipping beats (HR, 1.55; 95% confidence interval [CI], 1.29-1.86). The individual severities of heart racing or skipping beats, dizziness, tremors (shakes), feeling tired, forgetfulness, mood swings, restless or fidgety, and difficulty concentrating were associated with increased all-cause mortality. Moderate or severe dizziness had the largest HR (1.58; 95% CI, 1.24-2.01). Multiple symptom modeling via least absolute shrinkage and selection operator selected dizziness, heart racing, feeling tired, and joint pain as most predictive of CVD, whereas dizziness, tremors, and feeling tired were most predictive of all-cause mortality.

CONCLUSION

Among postmenopausal women with no known CVD at baseline, the severity of specific individual MS was significantly associated with incident CVD and mortality. Consideration of severe MS may enhance sex-specific CVD risk predication in future cohorts, but caution should be applied as severe MS could also indicate other health conditions.

USPSTF recommends aspirin to prevent CVD in adults 40 to 59 y as an individual decision; not recommended for adults ≥60 y

Davidson KW, Barry MJ, Mangione CM, et al. Aspirin use to prevent cardiovascular disease: US Preventive Services Task Force recommendation statement. JAMA. 2022;327:1577-84. 35471505.

Meta-analysis of randomized controlled trials examining the safety and efficacy of bempedoic acid

Funding Acknowledgements

Type of funding sources: None.

Introduction

Bempedoic acid (BA), an inhibitor of ATP citrate lyase, has emerged as a new therapy for patients with dyslipidemia. The objective of this study was to perform a meta-analysis of BA's safety and cholesterol lowering efficacy.

Methods

A meta-analysis was performed using RCTs testing the safety and efficacy of BA versus placebo. The primary analysis calculated the odds ratio (OR) and 95% confidence interval (CI) of any adverse events, muscular-related AEs including myopathy, muscle weakness, and myalgias, as well as serious AEs as self-defined by the individual RCT. Additionally, we evaluated the mean difference (MD) and CI of low density lipoprotein-cholesterol (LDL-C), non-high density lipoprotein-cholesterol (non-HDL-C), total cholesterol (TC), and apolipoprotein B (ApoB) at 12 weeks, as well as LDL-C at 24 weeks of BA use as compared to placebo.

Results

Four RCTs were identified comparing BA to placebo. There was no increased risk of any AE [OR 1.04; 95%CI 0.89, 1.22], serious AE [OR 1.07; 95%CI 0.87, 1.34], or muscular-related AE [OR 1.25; 95%CI 0.98, 1.58] with BA use compared to placebo. BA resulted in a significant reduction in LDL-C [MD -21.06; 95%CI -24.49, -17.62], TC [MD -16.02; 95%CI -19.09, -12.93], non-HDL-C [MD -17.84; 95%CI -21.34, -14.34], and ApoB [MD -14.19; 95%CI -17.18, -11.21] at 12 weeks, and LDL-C at 24 weeks [MD -16.42; 95%CI -18.15, -14.69] compared to placebo.

Conclusion

In this meta-analysis testing BA versus placebo, BA significantly reduced levels of LDL-C, TC, non-HDL-C, and ApoB at 12 weeks and LDL-C at 24 weeks, and was not associated with an increased risk of any AE, muscular-related AE or serious AE. Further studies with longer time of follow up are needed to confirm the safety and long term cholesterol effects of BA.

Meta-Analysis of Nonrandomized Studies to Assess the Optimal Timing of Coronary Artery Bypass Grafting After Acute Myocardial Infarction

The optimal timing of coronary artery bypass grafting (CABG) in patients after an acute myocardial infarction (MI) is unknown. We performed a systematic review and meta-analysis of studies comparing mortality rates in patients who underwent CABG at different time intervals after acute MI. Bias assessments were completed for each study, and summary of proportions of all-cause mortality were calculated based on CABG at various time intervals after MI. A total of 22 retrospective studies, which included a total of 137,373 patients were identified. The average proportion of patients who died when CABG was performed within 6 hours of MI was 12.7%, within 6 to 24 hours of MI was 10.9%, within 1 day of MI was 9.8%, any time after 1 day of MI was 3.0%, within 7 days of MI was 5.9%, and any time after 7 days of MI was 2.7%. Interstudy heterogeneity, assessed using I² values, showed significant heterogeneity in death rates within subgroups. Only 1 study accounted for immortal time bias, and there was a serious risk of selection bias in all other studies. Confounding was found to be a serious risk for bias in 55% of studies because of a lack of accounting for type of MI, MI severity, or other verified cardiac risk factors. The current publications comparing timing of CABG after MI is at serious risk of bias because of patient selection and confounding, with heterogeneity in both study populations and intervention time intervals.

Association between coronary artery vitamin D receptor expression and select systemic risks factors for coronary artery atherosclerosis

OBJECTIVE

The aim of this study is to analyze the association between coronary artery vitamin D receptor (VDR) expression and systemic coronary artery atherosclerosis (CAA) risk factors.

METHODS

Female cynomolgus monkeys (n = 39) consumed atherogenic diets containing the women's equivalent of 1000 IU/day of vitamin D₃. After 32 months consuming the diets, each monkey underwent surgical menopause. After 32 postmenopausal months, CAA and VDR expression were quantified in the left anterior descending coronary artery. Plasma 25OHD_3, lipid profiles and serum monocyte chemotactic protein-1 (MCP-1) were measured.

RESULTS

In postmenopausal monkeys receiving atherogenic diets, serum MCP-1 was significantly elevated compared with baseline (482.2 ± 174.2 pg/ml vs. 349.1 ± 163.2 pg/ml, respectively; p < 0.001; d = 0.79) and at the start of menopause (363.4 ± 117.2 pg/ml; p < 0.001; d = 0.80). Coronary VDR expression was inversely correlated with serum MCP-1 (p = 0.042). Additionally, the change of postmenopausal MCP-1 (from baseline to necropsy) was significantly reduced in the group with higher, compared to below the median, VDR expression (p = 0.038). The combination of plasma 25OHD₃ and total plasma cholesterol/high-density lipoprotein cholesterol was subsequently broken into low-risk, moderate-risk and high-risk groups; as the risk increased, the VDR quantity decreased (p = 0.04). CAA was not associated with various atherogenic diets.

CONCLUSION

Coronary artery VDR expression was inversely correlated with markers of CAA risk and inflammation, including MCP-1, suggesting that systemic and perhaps local inflammation in the artery may be associated with reduced arterial VDR expression.

Usefulness of Glucagon-Like Peptide-1 Receptor Agonists to Reduce Adverse Cardiovascular Disease Events in Patients with Type 2 Diabetes Mellitus

Evidence suggests glucagon-like peptide-1 receptor agonists (GLP-1 RA) reduce cardiovascular disease (CVD) events. The objective of this study was to analyze randomized controlled trials (RCT) testing GLP-1 RA's effect on CVD events among participants with type 2 diabetes (T2DM). RCTs comparing GLP-1 RA versus placebo were identified using the PubMed and Cochrane databases. The endpoints in this study included major adverse cardiovascular events (MACE; a composite of cardiovascular death, nonfatal myocardial infarction (MI), and nonfatal stroke), and the individual components of MACE. The primary analysis calculated risk ratios (RR) and 95% confidence intervals (CI) for each endpoint. Heterogeneity for each endpoint was calculated using Chi² and I² tests. For any endpoint with significant heterogeneity, a meta-regression was performed using mean baseline hemoglobin A1C (A1C) as the moderator and a R² value was calculated. Seven RCTs (N = 56,004) were identified with 174,163 patient-years of follow-up. GLP-1 RA reduced MACE [RR 0.89, 95% CI 0.83 to 0.95], cardiovascular death [RR 0.88, 95% CI 0.81 to 0.95], and nonfatal stroke [RR 0.85, 95% CI 0.77 to 0.95]. There was no statistically significant heterogeneity among these RCTs. GLP-1 RA did not reduce nonfatal MI [RR 0.91, 95% CI 0.81 to 1.02]. However, there was significant heterogeneity among these RCTs (Chi² = 12.68, p = 0.05, I² = 53%). When accounting for baseline A1C in the regression model, there was no longer significant heterogeneity for this endpoint (p = 0.23, I² = 27%). A potential linear relationship between baseline A1C and GLP-1 RA's effect on nonfatal MI (R² = 0.64) was observed. In conclusion, GLP-1 RA reduced MACE, cardiovascular death, and nonfatal stroke; GLP-1 RA did not reduce nonfatal MI, however there may be a linear association between baseline A1C and GLP-1 RA's effect on nonfatal MI.

Aspirin for Primary Atherosclerotic Cardiovascular Disease Prevention as Baseline Risk Increases: A Meta-Regression Analysis

BACKGROUND

Aspirin has long had a role in the primary prevention of atherosclerotic cardiovascular disease (ASCVD); however, recent randomized controlled trials (RCTs) have challenged this practice. Despite this, aspirin is still commonly recommended for high-risk primary prevention. We tested the hypothesis that aspirin is more efficacious for the primary prevention of ASCVD as the baseline risk increases.

METHODS

RCTs that compared aspirin with control for primary prevention and evaluated ASCVD (composite of myocardial infarction and ischemic stroke) and major bleeding were included. Rate ratios (RR) and 95% confidence intervals (CI) were calculated. A regression analysis was performed using the ASCVD event rate in the control arm of each RCT as the moderator.

RESULTS

Twelve RCTs were identified with 963,829 patient-years of follow-up. Aspirin was associated with a reduction in ASCVD (4.7 vs 5.3 events per 1000 patient-years; RR 0.86; 95% CI, 0.79-0.92). There was increased major bleeding among aspirin users (2.5 vs 1.8 events per 1000 patient-years; RR 1.41; 95% CI, 1.29-1.54). Regression analysis found no relationship between the log RR of ASCVD or major bleeding and rate of ASCVD in the control arm of each RCT.

CONCLUSION

Aspirin is associated with a reduction in ASCVD when used for primary prevention; however, it is unlikely to be clinically significant given the increase in bleeding. More importantly, aspirin's treatment effect does not increase as ASCVD risk increases, as many hypothesize. There is no suggestion from these data that use of aspirin for higher-risk primary prevention patients is beneficial.

A Meta-Regression Analysis of Atrial Fibrillation Ablation in Patients with Systolic Heart Failure

Background

Meta-analyses of randomized controlled trials comparing atrial fibrillation (AF) ablation to medical therapy in patients with heart failure (HF) reported improvement in left ventricular ejection fraction (LVEF), quality of life using the Minnesota Living with HF Questionnaire (MLWHFQ), and 6-minute walk test (6MWT). Nonetheless, there was significant heterogeneity not accounted for suggesting that not all HF patients derive the same effect from AF ablation.

Objectives

To evaluate if baseline LVEF or the etiology of the cardiomyopathy would moderate the efficacy of AF ablation.

Methods

We performed random effects meta-regression using the mean baseline LVEF and total percentage of patients with non-ischemic cardiomyopathy (NICMP) in the placebo arms as moderator variables.

Results

Six trials with a total of 687 patients were included. The baseline LVEF in the control arm of trials ranged from 25% - 42.9%, and the percentage of patients with NICMP within each trial varied from 35% to 100%. When baseline LVEF was used as the moderator variable, no significant change in heterogeneity was observed for any of the outcomes of interest (R2 0.00 - 0.02). However, when controlling for NICMP, heterogeneity dropped substantially for the outcomes of LVEF (I2 44.7%, R2 0.91), and MLWHFQ (I2 0.00%, R2 1.00) but not 6MWT (I2 67.4%, R2 0.00). This indicates that improvement in LVEF and MLWHFQ was greater in the AF ablation group when more patients with NICMP were included in the trials.

Conclusions

In patients with systolic HF, AF ablation may be more beneficial in patients with NICMP.

A systematic review and meta-regression analysis to examine the 'timing hypothesis' of hormone replacement therapy on mortality, coronary heart disease, and stroke

Background

The 'Timing Hypothesis' states that the benefits and harms of hormone replacement therapy (HRT) are related to the proximity with which it is begun following the onset of menopause. The primary aim of this analysis was to test for heterogeneity of treatment effect for HRT using Chi² and I² tests for younger versus older initiators of HRT. The secondary aim was to perform a meta-regression with mean age at trial baseline as the covariate for various outcomes.

Methods

Younger initiation trials were defined as those with mean age of participants <60 years and older initiation trials were those with mean age >60 years. The primary endpoints included all-cause mortality, cardiac mortality, coronary heart disease (CHD) events (a composite of cardiac mortality and nonfatal myocardial (MI)), and a composite of stroke, transient ischemic attack (TIA) and systemic embolism.

Results

Thirty-one RCTs were identified comparing HRT users to nonusers (n = 40,521). There was significant heterogeneity of treatment effect between younger versus older HRT initiators for all-cause mortality (Chi² = 9.74, p = 0.002, I² = 89.7%), cardiac mortality (Chi² = 4.04, p = 0.04, I² = 75.2%), and CHD events (Chi² = 3.06, p = 0.08, I² = 67.3%). Both groups experienced an increase in stroke, TIA and systemic embolism (1112/18,774 in the HRT group versus 734/18,070 in the control group; OR = 1.52; 95% confidence interval (CI) = 1.38-1.67). When performing the meta-regression, as age increased the treatment effect of HRT was increased for stroke, TIA and systemic embolism (point estimate 0.006 with a standard error of 0.002) (p = 0.0003).

Conclusion

Younger initiation of HRT may be effective in reducing death and cardiac events. However, younger HRT initiators remained at an increased risk of stroke, TIA and systemic embolism and this risk increased as average age increased. Younger menopausal women using HRT to treat vasomotor symptoms do not appear to be at an increased risk of dying or experiencing CHD events.

Vitamin D heritability and effect of pregnancy status in Vervet monkeys (Chlorocebus aethiops sabaeus) under conditions of modest and high dietary supplementation

OBJECTIVES

The two objectives of the current study were to: 1) investigate the genetic contributions to variations in serum vitamin D concentrations under two dietary conditions (a standard monkey biscuit diet vs. a diet designed to model typical American consumption); and 2) explore the interaction of vitamin D with pregnancy status using a cohort of pedigreed female vervet/African green monkeys.

METHODS

This study includes 185 female (≥3.5 years) vervet/African green monkeys (Chlorocebus aethiops sabaeus) from a multi-generational, pedigreed breeding colony. The 25(OH)D3 concentrations were first measured seven to eight weeks after consuming a "typical American" diet (TAD), deriving 37, 18, and 45% of calories from fat, protein sources, and carbohydrates, and supplemented with vitamin D to a human equivalent of 1,000 IU/day. Vitamin D concentrations were assessed again when animals were switched to a low-fat, standard biscuit diet (LabDiet 5038) for 8 months, which provided a human equivalent of approximately 4,000 IU/day of vitamin D. All statistical analyses were implemented in SOLAR.

RESULTS

Pregnancy was associated with reduced 25(OH)D3 concentrations. Heritability analyses indicated a significant genetic contribution to 25(OH)D3 concentrations in the same monkeys consuming the biscuit diet (h(2) =0.66, P=0.0004) and TAD (h(2) =0.67, P=0.0078) diets, with higher 25(OH)D3 concentrations in animals consuming the biscuit diet. Additionally, there was a significant genotype-by-pregnancy status interaction on 25(OH)D3 concentrations (P<0.05) only among animals consuming the TAD diet.

DISCUSSION

These results support the existence of a genetic contribution to differences in serum 25(OH)D3 concentrations by pregnancy status and emphasize the role of diet (including vitamin D supplementation) in modifying genetic signals as well as vitamin D concentrations.

Coronary artery vitamin D receptor expression and plasma concentrations of 25-hydroxyvitamin D: their association with atherosclerosis

OBJECTIVE

The aim of this study was to analyze coronary artery vitamin D receptor (VDR) expression, the plasma concentrations of 25-hydroxyvitamin D3 (25OHD3), and their relationship with coronary artery atherosclerosis.

METHODS

Premenopausal cynomolgus monkeys were fed atherogenic diets containing the equivalent of 1,000 IU/day of vitamin D3. Protein was derived from casein-lactalbumin (C/L, n = 10), soy protein isolate (soy, n = 10), or a combination (n = 19). After 32 months of consuming the diets, each monkey underwent surgical menopause. After 32 postmenopausal months, coronary atherosclerosis was measured in the left circumflex (LCX) artery and left anterior descending (LAD) artery. VDR expression was determined for the LAD, and 25OHD3 concentrations were assessed.

RESULTS

Both the cross-sectional area of atherosclerotic plaques (in square millimeters) and plaque thickness (in millimeters) in the LCX as well as the LAD arteries were analyzed in these monkeys. Those with higher plasma vitamin D3 concentrations and higher VDR were compared with those with higher plasma 25OHD3 concentrations and lower VDR. Significantly smaller plaque sizes were noted with higher plasma 25OHD3 concentrations and higher VDR. For the LCX artery, there was also a significantly lower plaque size (both plaque thickness and cross-sectional area) in those with higher quantities of VDR and lower 25OHD3 concentrations versus those with lower quantities of VDR and higher plasma concentrations of 25OHD3 (P = 0.009 and P = 0.040, respectively).

CONCLUSIONS

Cynomolgus monkeys with higher quantities of VDR have significantly less atherosclerosis than do those with lower quantities of VDR and higher plasma 25OHD3 concentrations. If these findings translate to human beings, it might explain why some individuals with higher plasma concentrations of 25OHD3 have more coronary artery atherosclerosis.

25(OH)D3 and cardiovascular risk factors in female nonhuman primates

OBJECTIVE

To determine if interindividual differences in plasma concentrations of 25-hydroxyvitamin D(3) (25(OH)D(3)) have pathophysiologic significance, we evaluated a cohort of female monkeys, seeking to identify associations with clinically relevant cardiovascular risk factors, including age, abdominal obesity (waist circumference), and high-density lipoprotein cholesterol (HDL-C).

METHODS

One hundred fifty-five female vervet monkeys (Chlorocebus aethiops sabaeus) aged 3-25 years consumed a typical western diet for 7-8 weeks that provided a woman's equivalent of approximately 1000 IU/day of vitamin D(3). Measurements of vitamin D(3) and HDL-C concentrations, as well as waist circumference, were obtained.

RESULTS

Among young monkeys (aged 3-5 years), compared to older monkeys (aged 16-25 years), the mean plasma 25(OH)D(3) concentrations were 82.3±3.2 ng/mL and 58.6±2.9 ng/mL (p<0.0001), respectively. Plasma 25(OH)D(3) concentrations had a range of 19.6-142.0 ng/mL (mean±standard error [SE] 66.4±1.7 ng/mL). 25(OH)D(3) concentrations were inversely associated with age (p<0.0001) and waist circumference (p=0.016) and were positively correlated with HDL-C (p=0.01). However, when statistically controlling for age, none of these relationships remained significant.

CONCLUSIONS

Higher plasma concentrations of 25(OH)D(3) were associated with more favorable cardiovascular risk factors, with inverse associations observed between 25(OH)D(3) and abdominal obesity, HDL-C, and age. These associations were no longer significant when controlling for age.

The quantification of vitamin D receptors in coronary arteries and their association with atherosclerosis

OBJECTIVE

The activated vitamin D receptor (VDR) may have an important role in vascular health. The objective of this study was to determine whether there is an association between the expression of VDRs in coronary arteries and the extent of diet-induced atherosclerosis.

METHODS

Utilizing a cohort of 39 postmenopausal female cynomolgus monkeys with varying stages of atherosclerosis, histologic sections of the left anterior descending artery (LAD) were analyzed for plaque cross-sectional area, plaque thickness, and VDR quantity using immunohistochemical H-score analysis. The quantities of VDRs were analyzed as a continuous variable and were divided at the median intimal H-score into high vs. low groupings.

RESULTS

In the LAD, a significant negative correlation was observed between the quantity of VDR and plaque size (both cross-sectional area [p<0.001] and plaque thickness [p<0.001]). Monkeys in the low VDR group had a significantly greater cross-sectional plaque area (1.2mm(2)) and greater plaque thickness (0.3mm) than those in the high VDR group (0.4mm(2), p=0.005; 0.1mm, p=0.003, respectively).

CONCLUSIONS

Lower concentrations of VDRs in a main coronary artery were associated with greater atherosclerotic plaque size in postmenopausal female monkeys. Given that coronary artery atherosclerosis is a major cause of coronary heart disease in postmenopausal women, further research to ascertain the relationship between VDRs and atherosclerosis is warranted.

Identification of a mechanism for increased cardiovascular risk among individuals with low vitamin D concentrations

OBJECTIVE

The aim of this study was to investigate the plasma concentrations of vitamin D and its association with plasma lipid profiles.

METHODS

Plasma vitamin D3 and lipid concentrations were measured in 119 female cynomolgus monkeys (premenopausal, n = 49; ovariectomized, n = 70) consuming approximately 1,000 IU per day of vitamin D3. In a subset of the ovariectomized monkeys (n = 23), vitamin D3 was remeasured after 6 months. The concentrations of vitamin D3 were analyzed as a continuous variable and were divided at the median into high (≥48 ng/mL) versus low (<48 ng/mL) groupings.

RESULTS

Among the 119 monkeys, the range of vitamin D3 concentrations was 24.0 to 95.2 ng/mL (mean ± SD, 48.5 ± 12.7 ng/mL). Plasma vitamin D3 concentration was positively associated with high-density lipoprotein cholesterol (HDL-C; P = 0.003). Monkeys in the high vitamin D3 group had a significantly greater plasma HDL-C concentration (57.9 mg/dL) than did those in the low vitamin D3 group (47.1 mg/dL; P = 0.001). Although the difference was not significant (P = 0.120), the monkeys in the high vitamin D3 group had a decreased total plasma cholesterol-to-HDL-C ratio compared with those in the low vitamin D3 group (5.4 and 6.2, respectively), potentially putting them at lower risk of atherosclerosis development.

CONCLUSIONS

Given that the monkeys all consumed a diet replete in vitamin D3, it seems that individual differences in vitamin D absorption or metabolism may have determined whether the monkeys had high or low concentrations of vitamin D3. Lower vitamin D3 was associated with a more atherogenic lipid profile, a major risk factor for progressing to coronary artery atherosclerosis in monkeys and human beings.