GLP-1 receptor agonists and atherosclerosis protection: the vascular endothelium takes center stage

Atherosclerotic cardiovascular disease is a chronic condition that often copresents with type 2 diabetes and obesity. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are incretin mimetics endorsed by major professional societies for improving glycemic status and reducing atherosclerotic risk in people living with type 2 diabetes. Although the cardioprotective efficacy of GLP-1RAs and their relationship with traditional risk factors are well established, there is a paucity of publications that have summarized the potentially direct mechanisms through which GLP-1RAs mitigate atherosclerosis. This review aims to narrow this gap by providing comprehensive and in-depth mechanistic insight into the antiatherosclerotic properties of GLP-1RAs demonstrated across large outcome trials. Herein, we describe the landmark cardiovascular outcome trials that triggered widespread excitement around GLP-1RAs as a modern class of cardioprotective agents, followed by a summary of the origins of GLP-1RAs and their mechanisms of action. The effects of GLP-1RAs at each major pathophysiological milestone of atherosclerosis, as observed across clinical trials, animal models, and cell culture studies, are described in detail. Specifically, this review provides recent preclinical and clinical evidence that suggest GLP-1RAs preserve vessel health in part by preventing endothelial dysfunction, achieved primarily through the promotion of angiogenesis and inhibition of oxidative stress. These protective effects are in addition to the broad range of atherosclerotic processes GLP-1RAs target downstream of endothelial dysfunction, which include systemic inflammation, monocyte recruitment, proinflammatory macrophage and foam cell formation, vascular smooth muscle cell proliferation, and plaque development.

Association of Cerebral Oximetry With Brain Ischemic Lesions and Functional Outcomes in Arch Repair

BACKGROUND

This exploratory analysis of the randomized controlled Aortic Surgery Cerebral Protection Evaluation CardioLink-3 trial sought to determine if cerebral oximetry desaturation during elective proximal arch repair is associated with detrimental postoperative neuroradiologic and neurofunctional outcomes.

METHODS

Cerebral oximetry and pre- and postoperative brain magnetic resonance imaging data from 101 participants were analyzed. Oximetry data from the trial allocation groups were compared; the relationships between cerebral oximetry indices and new ischemic cerebral lesions on magnetic resonance imaging and neurologic outcomes were also evaluated.

RESULTS

Total cerebral desaturation events (>20% decrease from baseline) on the left (median [interquartile range], 1 [1-3] vs 1.5 [0.5-3] with innominate and axillary cannulation; P = .80) were comparable to those on the right (1 [1-3] vs 1 [0-3]; P = .75) as were the total area under the curve of desaturation (left, P = .61; right, P = .84). Seventy patients had new ischemic lesions, among whom 36 had new severe lesions. Total desaturation events and area under the curve of desaturation were similar in patients with and without new ischemic lesions or severe lesions. The nadir regional cerebral saturation was lower on the left (49% [41-56]) than the right (53% [44-59]); left desaturation episodes were associated with lower postoperative cognitive test scores (P = .004).

CONCLUSIONS

The innominate and axillary cannulation techniques for elective proximal arch repair with unilateral antegrade cerebral perfusion were associated with similar occurrences of cerebral oximetry desaturation and neither were associated with new ischemic lesions.

Vascular Regenerative Cell Deficiencies in South Asian Adults

BACKGROUND

South Asian individuals shoulder a disproportionate burden of cardiometabolic diseases.

OBJECTIVES

The purpose of this study was to determine if vascular regenerative cell content varies significantly between South Asian and White European people.

METHODS

Between January 2022 and January 2023, 60 South Asian and 60 White European adults with either documented cardiovascular disease or established diabetes with ≥1 other cardiovascular risk factor were prospectively enrolled. Vascular regenerative cell content in venous blood was enumerated using a flow cytometry assay that is based on high aldehyde dehydrogenase (ALDHhi) activity and cell surface marker phenotyping. The primary outcome was the difference in frequency of circulating ALDHhi progenitor cells, monocytes, and granulocytes between the 2 groups.

RESULTS

Compared with White European participants, those of South Asian ethnicity were younger (69 ± 10 years vs 66 ± 9 years; P < 0.05), had lower weight (88 ± 19 kg vs 75 ± 13 kg; P < 0.001), and exhibited a greater prevalence of type 2 diabetes (62% vs 92%). South Asian individuals had markedly lower circulating frequencies of pro-angiogenic ALDHhiSSClowCD133+ progenitor cells (P < 0.001) and ALDHhiSSCmidCD14+CD163+ monocytes with vessel-reparative capacity (P < 0.001), as well as proportionally more ALDHhi progenitor cells with high reactive oxygen species content (P < 0.05). After correction for sex, age, body mass index, and glycated hemoglobin, South Asian ethnicity was independently associated with lower ALDHhiSSClowCD133+ cell count.

CONCLUSIONS

South Asian people with cardiometabolic disease had less vascular regenerative and reparative cells suggesting compromised vessel repair capabilities that may contribute to the excess vascular risk in this population. (The Role of South Asian vs European Origins on Circulating Regenerative Cell Exhaustion [ORIGINS-RCE]; NCT05253521).

Effect of empagliflozin on cardiac remodelling in South Asian and non-South Asian individuals: insights from the EMPA-HEART CardioLink-6 randomised clinical trial

BACKGROUND

This exploratory sub-analysis of the EMPA-HEART CardioLink-6 trial examined whether the previously reported benefit of the sodium-glucose cotransporter 2 (SGLT2) inhibitor empagliflozin on left ventricular (LV) mass (LVM) regression differs between individuals of South Asian and non-South Asian ethnicity.

METHODS

EMPA-HEART CardioLink-6 was a double-blind, placebo-controlled clinical trial that randomised 97 individuals with type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD) to either empagliflozin 10 mg daily or placebo for 6 months. LV parameters and function were assessed using cardiac magnetic resonance imaging. The 6-month changes in LVM and LV volumes, all indexed to baseline body surface area, for South Asian participants were compared to those for non-South Asian individuals.

RESULTS

Compared to the non-South Asian group, the South Asian sub-cohort comprised more males, was younger and had a lower median body mass index. The adjusted difference for LVMi change over 6 months was -4.3 g/m2 (95% confidence interval [CI], -7.5, -1.0; P = 0.042) for the South Asian group and -2.3 g/m2 (95% CI, -6.4, 1.9; P = 0.28) for the non-South Asian group (Pinteraction = 0.45). There was no between-group difference for the adjusted differences in baseline body surface area-indexed LV volumes and LV ejection fraction.

CONCLUSIONS

There was no meaningful difference in empagliflozin-associated LVM regression between South Asian and non-South Asian individuals living with T2DM and CAD in the EMPA-HEART CardioLink-6 trial.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02998970 (First posted on 21/12/ 2016).

Empagliflozin improves circulating vascular regenerative cell content in people without diabetes with risk factors for adverse cardiac remodeling

Sodium glucose-cotransporter 2 (SGLT2) inhibitors have been reported to reduce cardiovascular events and heart failure in people with and without diabetes. These medications have been shown to counter regenerative cell exhaustion in the context of prevalent diabetes. This study sought to determine if empagliflozin attenuates regenerative cell exhaustion in people without diabetes. Peripheral blood mononuclear cells were collected at the baseline and 6-mo visits from individuals randomized to receive empagliflozin (10 mg/day) or placebo who were participating in the EMPA-HEART 2 CardioLink-7 trial. Precursor cell phenotypes were characterized by flow cytometry for cell-surface markers combined with high aldehyde dehydrogenase activity to identify precursor cell subsets with progenitor (ALDHhi) versus mature effector (ALDHlow) cell attributes. Samples from individuals assigned to empagliflozin (n = 25) and placebo (n = 21) were analyzed. At baseline, overall frequencies of primitive progenitor cells (ALDHhiSSClow), monocyte (ALDHhiSSCmid), and granulocyte (ALDHhiSSChi) precursor cells in both groups were similar. At 6 mo, participants randomized to empagliflozin demonstrated increased ALDHhiSSClowCD133+CD34+ proangiogenic cells (P = 0.048), elevated ALDHhiSSCmidCD163+ regenerative monocyte precursors (P = 0.012), and decreased ALDHhiSSCmidCD86 + CD163- proinflammatory monocyte (P = 0.011) polarization compared with placebo. Empagliflozin promoted the recovery of multiple circulating provascular cell subsets in people without diabetes suggesting that the cardiovascular benefits of SGLT2 inhibitors may be attributed in part to the attenuation of vascular regenerative cell exhaustion that is independent of diabetes status.NEW & NOTEWORTHY Using an aldehyde dehydrogenase (ALDH) activity-based flow cytometry assay, we found that empagliflozin treatment for 6 mo was associated with parallel increases in circulating vascular regenerative ALDHhi-CD34/CD133-coexpressing progenitors and decreased proinflammatory ALDHhi-CD14/CD86-coexpressing monocyte precursors in individuals without diabetes but with cardiovascular risk factors. The rejuvenation of the vascular regenerative cell reservoir may represent a mechanism via which sodium glucose-cotransporter 2 (SGLT2) inhibitors limit maladaptive repair and delay the development and progression of cardiovascular diseases.

Wearable Cardiac Rhythm Monitoring Device for Detection of Postoperative Atrial Fibrillation

PURPOSE

This study evaluated the use of a wearable, patch-based cardiac rhythm monitoring device in detecting postoperative atrial fibrillation (POAF) among cardiac surgical patients within 30 days after hospital discharge.

DESCRIPTION

From the SEARCH-AF (The Post-Surgical Enhanced Monitoring for Cardiac Arrhythmias and Atrial Fibrillation) CardioLink-1 trial, this study examined rates of POAF according to surgery type and the incremental value of continuous cardiac rhythm monitoring among patients who underwent valve surgery. The primary outcome was cumulative atrial fibrillation or atrial flutter lasting for ≥6 minutes detected by continuous monitoring or atrial fibrillation or atrial flutter documented by a 12-lead electrocardiogram within 30 days of randomization.

EVALUATION

The primary outcome occurred in 8.2%, 13.5%, and 21.2% of patients who underwent isolated coronary artery bypass grafting (CABG), isolated valve surgery, and combined CABG and valve surgery. Relative to patients who underwent isolated CABG, those patients who had valve surgery were more likely to experience POAF. A higher diagnostic yield was obtained when the patch-based cardiac rhythm monitor was applied in patients who underwent valve surgery.

CONCLUSIONS

Use of a wearable, patch-based cardiac monitoring device was an effective detection strategy among patients undergoing valve surgery, given their higher risk of developing POAF.

Left ventricular mass predicts cardiac reverse remodelling in patients treated with empagliflozin

BACKGROUND

The cardiovascular (CV) benefits of sodium-glucose transport protein 2 inhibitors have been attributed, in part, to cardiac reverse remodelling. The EMPA-HEART CardioLink-6 study reported that sodium-glucose cotransporter-2 inhibition for 6 months with empagliflozin was associated with a significant reduction in left ventricular mass indexed to body surface area (LVMi). In this sub-analysis, we evaluated whether baseline LVMi may influence how empagliflozin affects cardiac reverse remodelling.

METHODS

A total of 97 patients with type 2 diabetes and coronary artery disease were randomized to empagliflozin (10 mg/d) or matching placebo for 6 months. The study cohort was divided into those whose baseline LVMi was ≤ 60 g/m² and those who had a baseline LVMi > 60 g/m². Subgroup comparisons were conducted using a linear regression model adjusted for baseline values (ANCOVA) that included an interaction term between LVMi subgroup and treatment.

RESULTS

Baseline LVMi was 53.3 g/m² (49.2-57.2) and 69.7 g/m² (64.2-76.1) for those with baseline ≤ 60 g/m² (n = 54) and LVMi > 60 g/m² (n = 43) respectively. The adjusted difference of LVMi regression between those randomized to empagliflozin and placebo were - 0.46 g/m² (95% CI: -3.44, 2.52, p = 0.76) in the baseline LVMi ≤ 60 g/m² subgroup and - 7.26 g/m² (95% CI: -11.40, -3.12, p = 0.0011) in the baseline LVMi > 60 g/m² subgroup (p-for-interaction = 0.007). No significant associations were found between baseline LVMi and 6-month change in LV end systolic volume-indexed (p-for-interaction = 0.086), LV end diastolic volume-indexed (p-for-interaction = 0.34), or LV ejection fraction (p-for-interaction = 0.15).

CONCLUSIONS

Patients with higher LVMi at baseline experienced greater LVM regression with empagliflozin.

Impact of diabetes duration on left ventricular mass regression with empagliflozin

AIMS

The duration of type 2 diabetes mellitus (T2DM) is an important determinant of diabetes severity. The EMPA-HEART CardioLink-6 trial reported significant left ventricular (LV) mass indexed to body surface area (LVMi) regression in patients treated with the sodium-glucose cotransporter 2 inhibitor (SGLT2i) empagliflozin for 6 months. This exploratory sub-analysis of the same trial investigated the association between T2DM duration and LVMi regression.

METHODS AND RESULTS

A total of 97 individuals with T2DM and coronary artery disease (CAD) were randomly assigned to receive empagliflozin 10 mg daily or placebo. LVMi was measured at the baseline and 6 month visit using cardiac magnetic resonance imaging. The study population was divided into those with a baseline T2DM duration <10 years (n = 40) or ≥10 years (n = 57). A linear model adjusting for baseline values in each of the subgroups (ANCOVA) was used to assess the treatment effect of 6 month change in LVMi, LV end systolic volume indexed to body surface area, LV end diastolic volume indexed to body surface area and LV ejection fraction. Patients in the T2DM duration <10 years group (38 males [95.0%], median age 63 [IQR: 55 years to 70 years]) had a median T2DM duration of 4 years (IQR: 2.0 years to 7.0 years). Those in the T2DM duration ≥10 years group (52 males [91.2%], median age 65 [IQR: 57 years to 71 years]) had a median duration of 15 years (IQR: 12 years to 20 years). There was no significant difference in baseline LVMi according to T2DM duration (median 62 g/m² [IQR: 53.1 g/m² to 70.0 g/m² ] for T2DM duration <10 years; median 57.5 g/m² [IQR: 52.1 g/m² to 66.2 g/m² ] for T2DM duration ≥10 years; P = 0.11). Empagliflozin was associated with reductions in LVMi irrespective of duration of T2DM above and below 10 years (T2DM duration <10 years group, mean adjusted difference -2.90 g/m² [95% CI: -6.64 g/m² to 0.84 g/m² ]; T2DM duration ≥10 years group, mean adjusted difference -3.69 g/m² [95% CI: -0.14 g/m² to -7.24 g/m² ]; P_interaction  = 0.07).

CONCLUSIONS

In the EMPA-HEART CardioLink-6 trial, empagliflozin treatment was associated with reductions in LVMi in people with T2DM and CAD irrespective of the duration of diabetes assessed categorically above and below 10 years.

IGFBP7 and left ventricular mass regression: a sub-analysis of the EMPA-HEART CardioLink-6 randomized clinical trial

AIMS

Given recent suggestions that serum levels of insulin-like growth factor-binding protein 7 (IGFBP7) may identify patients who derive greater cardiorenal benefits from treatment with sodium-glucose transport 2 inhibitors (SGLT2i), this exploratory sub-analysis of the EMPA-HEART CardioLink-6 randomized controlled trial evaluated the association between serum levels of IGFBP7 and empagliflozin-mediated left ventricular mass regression.

METHODS AND RESULTS

The EMPA-HEART CardioLink-6 trial used gold-standard cardiac magnetic resonance imaging to detect change in left ventricular mass indexed to body surface area (LVMi) following 6 months of treatment with empagliflozin or matching placebo in 97 patients with type 2 diabetes and coronary artery disease. Serum samples were collected at baseline and analysed for IGFBP7 using an enzyme-linked immunosorbent assay. A multivariate linear regression model was used to assess the association between IGFBP7 and baseline LVMi. A linear model adjusting for baseline differences in LVMi was used to test the relationship between baseline IGFBP7 level, change in LVMi over 6 months, and treatment arm. Of the 97 patients enrolled, 74 had complete covariate data and were included in our analysis. No association between baseline IGFBP7 and baseline LVMi was found [baseline LVMi: 0.14 g/m² (95% CI: -0.29 g/m² to 0.57 g/m² ) per 1 ng/mL higher baseline IGFBP7]. In addition, no difference between patients treated with empagliflozin versus matching placebo was found when evaluating the association between serum IGFBP7, 6 month change in LVMi, and treatment arm [empagliflozin 6 month change in LVMi: 0.25 g/m² (95% CI: -0.17 g/m² to 0.67 g/m² ) per 1 ng/mL higher IGFBP7 vs. matching placebo 6 month change in LVMi: 0.07 g/m² (95% CI: -0.21 g/m² to 0.35 g/m² ) per 1 ng/mL higher IGFBP7; P_interaction  = 0.49]. Additional sensitivity analysis assessing IGFBP7 as a categorical variable (above/below the median) showed no significant association between IGFBP7, 6 month change in LVMi, and treatment arm.

CONCLUSIONS

Our study provides insight into the generalizability of IGFBP7 as a surrogate marker of cardiac remodelling in patients with type 2 diabetes and coronary artery disease. Our results suggest that SGLT2i-mediated reverse cardiac remodelling may be independent of IGFBP7 levels. Further investigations evaluating the association between IGFBP7 and SGLT2i are suggested to understand if and how IGFBP7 levels may modulate benefits received from SLGT2i.

Baseline neutrophil-to-lymphocyte ratio and efficacy of SGLT2 inhibition with empagliflozin on cardiac remodelling

AIMS

The neutrophil-to-lymphocyte ratio (NLR) is a marker of systemic inflammation and plays a critical role in the assessment and prognosis in patients with heart failure. The EMPA-HEART CardioLink-6 trial demonstrated that patients with type 2 diabetes (T2D) and coronary artery disease (CAD) treated with a sodium-glucose transport protein 2 inhibitor for 6 months experienced regression in left ventricular mass. Given this, we evaluated the relationship of baseline NLR and cardiac reverse remodelling in the entire cohort of this trial.

METHODS AND RESULTS

A total of 97 individuals were randomized to receive empagliflozin (10 mg/day) or placebo for 6 months. The primary outcome of the trial was change in left ventricular mass indexed to body surface area (LVMi) from baseline to 6 months as measured by cardiac magnetic resonance imaging. In our analysis, the cohort was stratified above and below an NLR level of 2. To assess the treatment effect on the 6 month change in NLR, we used a linear model adjusting for baseline differences in NLR [analysis of covariance (ANCOVA)] that included an interaction term between the baseline NLR and treatment. To assess the treatment effect on the 6 month change in LVMi in each of the subgroups divided by baseline NLR, we used an ANCOVA adjusting for baseline differences in LVMi that included an interaction term between the subgroups and treatment. The results of the regression models were summarized as adjusted differences with two-sided 95% confidence intervals (CIs). Patients who exhibited an elevated baseline NLR demonstrated higher LVMi and left ventricular end-diastolic volume indexed to body surface area than those with a lower NLR. In patients with an NLR < 2 and NLR ≥ 2, the adjusted difference in LVMi between the empagliflozin- and placebo-treated patients was -2.98 g/m² (95% CI: -6.18 to 0.22 g/m² ) (P value = 0.067) and -4.43 g/m² (95% CI: -8.50 to -1.11 g/m² ), respectively (P_interaction  = 0.60).

CONCLUSIONS

Empagliflozin treatment is associated with consistent reductions in LVMi in patients with T2D and CAD independent of baseline NLR.

Generalizability of the REDUCE-IT trial to South Asians with cardiovascular disease

BACKGROUND

South Asians (SAs) represent ∼25% of the world's population and account for >50% of global cardiovascular (CV) deaths, yet they continue to be underrepresented in contemporary clinical trials. The REDUCE-IT study demonstrated in a high-risk and predominantly White population that icosapent ethyl (IPE) lowered major adverse cardiovascular events by 25%. We sought to determine the generalizability of these results to a high-risk population of SAs with established CV disease living in Canada.

METHODS

This was a cross-sectional observational study of 200 statin-treated SAs (≥45 years) with atherosclerotic CV disease (ASCVD) (NCT05271591). SA ethnicity was self-identified as being of Anglo-Indian, Bangladeshi, Bengali, Bhutanese, Goan, Gujarati, Indian, Jatt, Kashmiri, Maharashtrian, Malayali, Nepali, Pakistani, Punjabi, Sindhi, Sinhalese, Sri Lankan, Tamil, Telugu, or other SA. ASCVD was defined as the presence of coronary, carotid, or peripheral atherosclerosis.

FINDINGS

Mean age of the cohort was 67 years, where 82% were men and 57% had diabetes. The predominant ASCVD phenotype was coronary artery disease (94%). Mean (SD) baseline LDL-C and triglycerides were 1.70 (0.8) mmol/L and 1.42 (1.0) mmol/L, respectively. Three-quarters were on high-intensity statin therapy. According to the Health Canada/Canadian Cardiovascular Society Guidelines and FDA-approved indication, 33% and 25% of the participants were, respectively, eligible for IPE.

CONCLUSIONS

A large proportion of high-intensity, statin-treated, high-risk patients with ASCVD and of self-reported SA ethnicity are eligible for IPE. These data have important translational implications for SAs who are at a disproportionately higher risk of CV morbidity and mortality.

FUNDING

This study was funded by an unrestricted grant provided by HLS Therapeutics Inc, Canada.

Predictors of mitral valve haemodynamics after mitral valve repair for degenerative mitral regurgitation

OBJECTIVE

Intraoperative predictors of functional mitral valve (MV) stenosis after surgical repair of mitral regurgitation (MR) caused by prolapse remain poorly characterised. This study evaluated the effect of annuloplasty size on postoperative MV haemodynamics during exercise and evaluated predictors of MV hemodynamics.

METHODS

104 patients were randomly assigned to leaflet resection or preservation for surgical repair of MR in the Canadian Mitral Research Alliance CardioLink-2 study. In this post hoc analysis, we compared MV haemodynamics between the two surgical groups and examined the relationship between annuloplasty size and MV haemodynamics 1 year after repair in the combined groups. Echocardiograms were performed at baseline and intraoperatively. Exercise transthoracic echocardiography was performed 1 year postoperatively. Multivariable linear regression analysis was used to identify predictors of exercise MV gradients at follow-up.

RESULTS

Mean age of participants was 65±10 years, and 83% were male. Median annuloplasty size was 34 (IQR 32-36). Dividing by the median, 48 (46%) had annuloplasty size of <34 mm and 56 (54%) had ≥34 mm. Mean and peak exercise gradients at 1 year were 11±5 mm Hg and 22±9 mm Hg in <34, and 6±3 mm Hg and 14±5 mm Hg in ≥34 (p<0.001). Rate of residual MR was similar in both groups. In multivariable analyses, annuloplasty size of ≥34 mm was associated with lower mean and peak exercise gradients at 12 months, after adjustment for repair type, age, sex, heart rate and body surface area (β -4.1, 95% CI -6 to -3, p<0.001, and β -7 95% CI -10 to -4, p<0.001, respectively). Intraoperative mean and peak MV gradients by transesophageal echocardiography independently predicted mean and peak resting and exercise gradients at follow-up (p<0.001). Similar results were obtained in both leaflet resection and preservation.

CONCLUSION

Annuloplasty size of ≥34 mm is associated with a 4 and 7 mm Hg reduction in mean and peak exercise MV gradients, respectively, 1 year post MV repair regardless of the repair strategy used. Intraoperative TEE MV gradients predict exercise MV gradients 1 year post repair.

TRIAL REGISTRATION NUMBER

NCT02552771.

Risk Factors for Postrepair Elevated Mitral Gradient: A Post-hoc Analysis of a Randomized Trial

BACKGROUND

Predischarge elevated mean mitral gradients (>5 mm Hg) may occur after repair for degenerative mitral regurgitation. We sought to identify risk factors associated with elevated gradients and to evaluate its impact on functional outcomes at 12 months in this subanalysis of the Canadian Mitral Research Alliance CardioLink-2 trial.

METHODS

One hundred four patients with degenerative mitral regurgitation undergoing mitral repair were randomized to either a leaflet resection or preservation strategy. Logistic regression was used to identify risk factors associated with an elevated gradient. Functional outcomes at 12 months were compared between participants with and without elevated gradients.

RESULTS

Elevated gradients was identified in 15 participants (14.4%), which was not significantly different based on allocation to each repair strategy (P = .10). Patients with elevated gradients were more likely to be women (odds ratio [OR], 4.28; 95% confidence interval [CI], 1.29-14.19; P = .02) and to have a lower preoperative hemoglobin level (OR, 0.93; 95% CI, 0.89-0.98; P = .01) and smaller intercommissural diameter (OR, 0.86; 95% CI, 0.76-0.97; P = .02) and mitral annuloplasty size (OR, 0.71; 95% CI, 0.57-0.87; P = .001). The ratio of intercommissural diameter-to-annuloplasty size was similar between those with and without elevated gradients (both 0.8 ± 0.1, P = .69). At 12 months those with elevated gradients had a worse New York Heart Association functional status (P = .0001), lower peak oxygen saturation in exercise test (P = .01), smaller body weight-walk distance product (P = .02), and higher Borg scale (P = .01) in the 6-minute walk test.

CONCLUSIONS

Female gender, smaller mitral anatomy sizes, and lower preoperative hemoglobin levels were associated with postoperative elevated mitral gradients, which was in turn were associated with reduced functional status. Further research is warranted to investigate these potential risk factors.

Empagliflozin and Left Ventricular Remodeling in People Without Diabetes: Primary Results of the EMPA-HEART 2 CardioLink-7 Randomized Clinical Trial

BACKGROUND

Sodium-glucose cotransporter 2 inhibitors have been demonstrated to promote reverse cardiac remodeling in people with diabetes or heart failure. Although it has been theorized that sodium-glucose cotransporter 2 inhibitors might afford similar benefits in people without diabetes or prevalent heart failure, this has not been evaluated. We sought to determine whether sodium-glucose cotransporter 2 inhibition with empagliflozin leads to a decrease in left ventricular (LV) mass in people without type 2 diabetes or significant heart failure.

METHODS

Between April 2021 and January 2022, 169 individuals, 40 to 80 years of age, without diabetes but with risk factors for adverse cardiac remodeling were randomly assigned to empagliflozin (10 mg/d; n=85) or placebo (n=84) for 6 months. The primary outcome was the 6-month change in LV mass indexed (LVMi) to baseline body surface area as measured by cardiac magnetic resonance imaging. Other measures included 6-month changes in LV end-diastolic and LV end-systolic volumes indexed to baseline body surface area and LV ejection fraction.

RESULTS

Among the 169 participants (141 men [83%]; mean age, 59.3±10.5 years), baseline LVMi was 63.2±17.9 g/m² and 63.8±14.0 g/m² for the empagliflozin- and placebo-assigned groups, respectively. The difference (95% CI) in LVMi at 6 months in the empagliflozin group versus placebo group adjusted for baseline LVMi was -0.30 g/m² (-2.1 to 1.5 g/m²; P=0.74). Median baseline (interquartile range) NT-proBNP (N-terminal-pro B-type natriuretic peptide) was 51 pg/mL (20-105 pg/mL) and 55 pg/mL (21-132 pg/mL) for the empagliflozin- and placebo-assigned groups, respectively. The 6-month treatment effect of empagliflozin versus placebo (95% CI) on blood pressure and NT-proBNP (adjusted for baseline values) were -1.3 mm Hg (-5.2 to 2.6 mm Hg; P=0.52), 0.69 mm Hg (-1.9 to 3.3 mm Hg; P=0.60), and -6.1 pg/mL (-37.0 to 24.8 pg/mL; P=0.70) for systolic blood pressure, diastolic blood pressure, and NT-proBNP, respectively. No clinically meaningful between-group differences in LV volumes (diastolic and systolic indexed to baseline body surface area) or ejection fraction were observed. No difference in adverse events was noted between the groups.

CONCLUSIONS

Among people with neither diabetes nor significant heart failure but with risk factors for adverse cardiac remodeling, sodium-glucose cotransporter 2 inhibition with empagliflozin did not result in a meaningful reduction in LVMi after 6 months.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04461041.

Acute Infarcts on Brain MRI Following Aortic Arch Repair With Circulatory Arrest: Insights From the ACE CardioLink-3 Randomized Trial

BACKGROUND

to investigate the frequency and distribution of new ischemic brain lesions detected by diffusion-weighted imaging on brain magnetic resonance imaging after aortic arch surgery.

METHODS

This preplanned secondary analysis of the randomized, controlled ACE (Aortic Surgery Cerebral Protection Evaluation) CardioLink-3 trial compared the safety and efficacy of innominate versus axillary artery cannulation during elective proximal aortic arch surgery. Participants underwent pre and postoperative magnetic resonance imaging. New ischemic lesions were defined as lesions visible on postoperative, but not preoperative diffusion weighted imaging.

RESULTS

Of the 111 trial participants, 102 had complete magnetic resonance imaging data. A total of 391 new ischemic lesions were observed on diffusion-weighted imaging in 71 (70%) patients. The average number of lesions in patients with ischemic lesion were 5.5±4.9 with comparable numbers in the right (2.9±2.0) and left (3.0±2.3) hemispheres (P=0.49). Half the new lesions were in the middle cerebral artery territory; 63% of the cohort had ischemic lesions in the anterior circulation, 49% in the posterior circulation, 42% in both, and 20% in watershed areas. A probability mask of all diffusion-weighted imaging lesions revealed that the cerebellum was commonly involved. More severe white matter hyperintensity on preoperative magnetic resonance imaging (odds ratio, 1.80 [95% CI, 1.10-2.95]; P=0.02) and lower nadir nasopharyngeal temperature during surgery (odds ratio per 1°C decrease, 1.15 [95% CI, 1.00-1.32]; P=0.05) were associated with the presentation of new ischemic lesion; older age (risk ratio per 1-year increase, 1.02 [95% CI, 1.00-1.04]; P=0.03) and lower nadir temperature (risk ratio per 1°C decrease, 1.06 [95% CI, 1.00-1.14]; P=0.06) were associated with greater number of lesions.

CONCLUSIONS

In patients who underwent elective proximal aortic arch surgery, new ischemic brain lesions were common, and predominantly involved the middle cerebral artery territory or cerebellum. Underlying small vessel disease, lower temperature nadir during surgery, and advanced age were risk factors for perioperative ischemic lesions.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02554032.

The impact of statins on post-discharge atrial fibrillation after cardiac surgery: Secondary analysis from a randomized trial

Background

Whether statins reliably reduce the risk of postoperative atrial fibrillation (POAF) in patients undergoing cardiac surgery remains controversial. We sought to determine the impact of statin use on new-onset postdischarge POAF in the Post-Surgical Enhanced Monitoring for Cardiac Arrhythmias and Atrial Fibrillation (SEARCH-AF) CardioLink-1 randomized controlled trial.

Methods

We randomized 336 patients with risk factors for stroke (CHA₂DS₂-VASc score ≥ 2) and no history of preoperative atrial fibrillation (AF) to 30-day continuous cardiac rhythm monitoring after discharge from cardiac surgery with a wearable, patched-based device or to usual care. The primary endpoint was the occurrence of cumulative AF and/or atrial flutter lasting for ≥ 6 minutes detected by continuous monitoring, or AF and/or atrial flutter documented by a 12-lead electrocardiogram within 30 days of randomization.

Results

The 260 patients (77.4%) discharged on statins were more likely to be male (P = 0.018) and to have lower CHA₂DS₂-VASc scores (P = 0.011). Patients treated with statins at discharge had a 2-fold lower rate of POAF than those who were not treated with statins in the entire cohort (18.4% vs 8.1%, log-rank P = 0.0076). On multivariable Cox regression including the CHA₂DS₂-VASc score adjustment, statin use was associated with a lower risk of POAF (hazard ratio 0.43, 95% confidence interval: 0.25-0.98, P = 0.043). Use of statins at a higher intensity was associated with lower risk of POAF, suggestive of a dose-response effect (log-rank P _trend = 0.0082).

Conclusions

The use of statins was associated with a reduction in postdischarge POAF risk among patients undergoing cardiac surgery. The routine use of high-intensity statin to prevent subacute POAF after discharge deserves further study.

Predictors of mitral valve hemodynamics after mitral valve repair for degenerative mitral regurgitation: a subanalysis of the CAMRA randomized trial

Introduction

Intra-operative predictors of mid-to-late mitral valve dysfunction after surgical repair of mitral regurgitation (MR) caused by prolapse remain poorly characterized. This study aims to evaluate the effect of annuloplasty prosthesis size on post-operative MV hemodynamics at rest and during exercise, and to identify perioperative predictors of MV dysfunction.

Methods

104 patients were randomly assigned to resection and preservation for surgical treatment of posterior leaflet prolapse in the Canadian Mitral Research Alliance CardioLink-2 study. Echocardiograms were performed at baseline and 1 year postoperatively. Intraoperative TEE was performed to assess immediate MV gradients. Exercise TTE was performed 1 year after repair. Linear regression analysis was used to identify associations between MV indices (rest and peak exercise gradients) at 12 months, and perioperative echocardiographic and clinical factors.

Results

Mean age of participants was 65±10 years, and 83% were male. Larger annuloplasty size was associated with lower transmitral gradients at rest and during peak exercise. In multivariable analysis, annuloplasty size ≥34mm was associated with lower mean and peak rest and exercise gradients at 12 months, after adjustment for repair type, age, sex, and BSA (p&lt;0.001). Higher pre-operative pulmonary artery pressures were associated with reduced functional capacity post-operatively. Intra-operative TEE gradients predict resting and exercise MV hemodynamics at 1 year.

Conclusion

Annuloplasty size ≥34mm is associated with improved MV hemodynamics at rest and during peak exercise 1 year post MV repair. MV repair prior to onset of pulmonary hypertension confers favourable post operative functional capacity. Finally, intra-operative TEE can be used to identify patients at risk of mitral valve dysfunction within 1 year of repair.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): The Heart and StrokeFoundation of Ontario (GIA 16-00014666)

Impact of diabetes and glucose-lowering therapy on post-operative atrial fibrillation after cardiac surgery: secondary analysis of the SEARCH-AF CardioLink-1 randomized clinical trial

Background

Diabetes mellitus is an important risk factor for atrial fibrillation (AF) and is associated with an increased risk of complications for patients with AF. The impact of diabetes on post-operative AF after cardiac surgery is not well-defined.

Purpose

We sought to characterize the effect of diabetes, insulin, and oral hypoglycemic agents on the incidence of post-operative atrial fibrillation (POAF) after cardiac surgery. Accordingly, we conducted a secondary analysis of the Post-Surgical Enhanced Monitoring for Cardiac Arrhythmias and Atrial Fibrillation (SEARCH-AF) CardioLink-1 randomized trial.

Methods

In the SEARCH-AF trial, 336 patients with risk factors for stroke (CHA2DS2-VASc score ≥2) and no history of preoperative AF were randomized to usual care or continuous cardiac rhythm monitoring for 30 days after discharge from cardiac surgery with a wearable, patched-based device. The primary outcome was occurrence of cumulative atrial fibrillation/flutter (AF/AFL) lasting for ≥6 minutes detected by continuous monitoring or AF/AFL documented by a 12-lead electrocardiogram within 30 days of randomization. We assessed the association between diabetes and occurrence of post-operative AF. In addition, we examined the association between POAF and glucose-lowering therapy among patients with diabetes.

Results

Among the 176 (52%) patients with diabetes in the study cohort, 80 (45%) patients were treated with at least 1 oral hypoglycemic agent and 44 (25%) patients were treated with insulin. The incidence of POAF occurring within 30 days after discharge from surgery was similar between patients with or without diabetes (cumulative incidence: 10.8% vs. 10.0%, log-rank p=0.77). Among patients with diabetes, the incidence of POAF was highest in those who were not treated with glucose-lowering therapy (17.3%) when compared with those treated with oral hypoglycemic agents (10.0%) or insulin (4.5%) (log-rank ptrend=0.045 among the 3 groups). In an exploratory analysis, we observed a trend suggesting a lower incidence of POAF among cardiac surgical patients who were treated with SGLT-2 inhibitors (log-rank ptrend=0.084).

Conclusion

The incidence of POAF occurring after discharge from cardiac surgery is equally high among patients with or without diabetes. Our results suggest a potential association between specific glucose-lowering therapies and risk of POAF after cardiac surgery, meriting further investigations.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Heart and Stroke Foundation of Canada

Valvular surgery is associated with an increased risk of post-operative atrial fibrillation: secondary analysis of the SEARCH-AF CardioLink-1 randomized trial

Background

Patients undergoing valve surgery have a higher risk of developing post-operative atrial fibrillation (POAF) relative to those undergoing isolated coronary artery bypass grafting (CABG). Whether this risk extends beyond hospital discharge is unknown.

Purpose

We examined the association between surgery type (isolated CABG vs. valve repair/replacement) on the incidence of post-operative atrial fibrillation (POAF) by conducting a secondary analysis of the Post-Surgical Enhanced Monitoring for Cardiac Arrhythmias and Atrial Fibrillation (SEARCH-AF) CardioLink-1 randomized trial.

Methods

In the SEARCH-AF trial, 336 patients with risk factors for stroke (CHA2DS2-VASc score ≥2) and no history of preoperative AF were randomized to usual care or continuous cardiac rhythm monitoring for 30 days after discharge from cardiac surgery with a wearable, patched-based device. The primary outcome was occurrence of cumulative atrial fibrillation/flutter (AF/AFL) lasting for ≥6 minutes detected by continuous monitoring or AF/AFL documented by a 12-lead ECG within 30 days of randomization. We compared the risk of POAF between patients who underwent CABG vs. valve repair/replacement. Patients who experienced post-operative AF during hospitalization were excluded from this analysis.

Results

The overall cohort consisted of 255, 39, and 42 patients who underwent isolated CABG, isolated valve replacement/repair, and CABG + valve repair/replacement, respectively. Baseline characteristics were similar among the groups except for younger age (p=0.0014), higher prevalence of preoperative myocardial infarction (p=0.002) and lower ejection fraction (p=0.025) in the isolated CABG group. Eighteen patients experienced post-operative AF during hospitalization. Patients who underwent CABG + valve surgery or isolated valve surgery were more likely to experience post-operative AF compared with those who underwent isolated CABG (Log-Rank ptrend=0.0096). Among patients who were randomized to continuous cardiac rhythm monitoring, the probability of post-operative AF among patients who underwent isolated CABG, valve surgery, and CABG + valve surgery was 15.8%, 29.4%, and 35.0%, respectively (Log-Rank ptrend=0.017). After multivariable adjustment, the risk of developing post-operative AF within 30 days after discharge remained higher among patients who underwent valve surgery compared with those who underwent isolated CABG (hazard ratio (HR) 2.22, 95% CI 1.01–4.87. Patients who underwent CABG + repair/replacement had the highest risk of experiencing post-operative AF when compared to patients who underwent isolated CABG (HR 2.78, 95% CI 1.12–6.86).

Conclusion

Patients undergoing valve repair or bioprosthetic valve replacement have a substantial risk of post-operative AF within 30 days after discharge from surgery. An aggressive cardiac rhythm monitoring strategy during this vulnerable period should be considered for this high-risk patient population.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Heart and Stroke Foundation of Canada

The impact of statin on post-operative atrial fibrillation after discharge from cardiac surgery: secondary analysis of the SEARCH-AF CardioLink-1 randomized trial

Background

There is conflicting evidence regarding the use of statins to reduce the risk of post-operative atrial fibrillation (POAF) in patients undergoing cardiac surgery.

Purpose

We sought to determine the effects of statin use on the burden of new-onset post-discharge POAF in the Post-Surgical Enhanced Monitoring for Cardiac Arrhythmias and Atrial Fibrillation (SEARCH-AF) CardioLink-1 randomized controlled trial.

Methods

In the SEARCH-AF trial, 336 patients with risk factors for stroke (CHA2DS2-VASc score ≥2) and no history of preoperative AF were randomized to usual care or continuous cardiac rhythm monitoring for 30 days after discharge from cardiac surgery with a wearable, patched-based device. The primary endpoint was the occurrence of cumulative atrial fibrillation/flutter (AF/AFL) lasting for ≥6 minutes detected by continuous monitoring or AF/AFL documented by a 12-lead electrocardiogram within 30 days of randomization. Using time-to-event analysis and Cox regression, we evaluated the association between the risk of post-operative AF in relation to statin use and dosing intensity (low, moderate, high) at the time of discharge. We excluded patients who experienced post-operative AF during hospitalization in this analysis.

Results

In the overall cohort (n=336), 260 (77.4%) patients were treated with statins at the time of hospital discharge. There were 18 (5.4%) patients who experienced post-operative AF during hospitalization. Patients prescribed with statins were more likely to be male (p=0.018), had lower CHA2DS2-VASc scores (p=0.011), and were more likely to undergo isolated coronary artery bypass grafting (CABG) (p=0.083). Baseline characteristics were otherwise similar between the 2 groups. Patients treated with statins at discharge had a 2-fold lower rate of post-operative AF than those who were not treated with statins in the overall cohort (17.6% vs. 8.2%, Log-Rank p=0.017) and among those who were randomized to continuous cardiac rhythm monitoring (31.6% vs. 16.0%, Log-Rank p=0.027) (Figure). After adjusting for surgery type (CABG vs. valve surgery) and the CHA2DS2-VASc score, statin use at discharge was associated with a lower risk of post-operative AF within 30 days after surgery (hazard ratio 0.48, 95% CI 0.24–0.97). Furthermore, increasing intensity of statin therapy was associated with lower risk of POAF (ptrend=0.0012) (Figure 1)

Conclusion

Among cardiac surgery patients with risk factors for stroke and no history of pre-operative AF, the use of statins was associated with a reduction in post-operative AF risk within 30 days of discharge. The routine use of high-intensity statin to prevent post-operative AF after cardiac surgery deserves further study.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Heart and Stroke Foundation of Canada

Stage-based approach to predict left ventricular reverse remodeling after mitral repair

Background

Although predictors of reverse left ventricular (LV) remodeling postmitral valve repair are critical for guiding perioperative decision‐making, there remains a paucity of randomized, prospective data to support the criteria that potential predictor variables must meet.

Methods and Results

The CAMRA CardioLink‐2 randomized trial allocated 104 patients to either leaflet resection or preservation strategies for mitral repair. The correlation of indexed left ventricular end‐systolic volume (LVESVI), indexed left ventricular end‐diastolic volume (LVEDVI), and left ventricular ejection fraction (LVEF) were tested with univariate analysis and subsequently with multivariate analysis to determine independent predictors of reverse remodeling at discharge and at 12 months postoperatively. At discharge, both LVESVI and LVEDVI were independently associated with their preoperative values (p < .001 for both) and LVEF by preoperative LVESVI (p < .001). Mitral ring size was favorably associated with the change in LVESVI (p < .05) and LVEF (p < .01) from predischarge to 12 months, while the mean mitral valve gradient after repair was adversely associated with the change in LVESVI (p < .05) and LVEDVI (p < .05). No significant associations were found between reverse remodeling and coaptation height nor mitral repair technique.

Conclusions

Beyond confirming the lack of impact of mitral repair technique on reverse remodeling, this investigation suggests that recommending surgery before significant LV dilatation or dysfunction, as well as higher postoperative mitral valve hemodynamic performance, may enhance remodeling capacity following mitral repair.

Lessons from bariatric surgery: Can increased GLP-1 enhance vascular repair during cardiometabolic-based chronic disease?

Type 2 diabetes (T2D) and obesity represent entangled pandemics that accelerate the development of cardiovascular disease (CVD). Given the immense burden of CVD in society, non-invasive prevention and treatment strategies to promote cardiovascular health are desperately needed. During T2D and obesity, chronic dysglycemia and abnormal adiposity result in systemic oxidative stress and inflammation that deplete the vascular regenerative cell reservoir in the bone marrow that impairs blood vessel repair and exacerbates the penetrance of CVD co-morbidities. This novel translational paradigm, termed 'regenerative cell exhaustion' (RCE), can be detected as the depletion and dysfunction of hematopoietic and endothelial progenitor cell lineages in the peripheral blood of individuals with established T2D and/or obesity. The reversal of vascular RCE has been observed after administration of the sodium-glucose cotransporter-2 inhibitor (SGLT2i), empagliflozin, or after bariatric surgery for severe obesity. In this review, we explore emerging evidence that links improved dysglycemia to a reduction in systemic oxidative stress and recovery of circulating pro-vascular progenitor cell content required for blood vessel repair. Given that bariatric surgery consistently increases systemic glucagon-like-peptide 1 (GLP-1) release, we also focus on evidence that the use of GLP-1 receptor agonists (GLP-1RA) during obesity may act to inhibit the progression of systemic dysglycemia and adiposity, and indirectly reduce inflammation and oxidative stress, thereby limiting the impact of RCE. Therefore, therapeutic intervention with currently-available GLP-1RA may provide a less-invasive modality to reverse RCE, bolster vascular repair mechanisms, and improve cardiometabolic risk in individuals living with T2D and obesity.

A randomized trial of icosapent ethyl in ambulatory patients with COVID-19

The coronavirus disease 2019 (COVID-19) pandemic remains a source of considerable morbidity and mortality throughout the world. Therapeutic options to reduce symptoms, inflammatory response, or disease progression are limited. This randomized open-label trial enrolled 100 ambulatory patients with symptomatic COVID-19 in Toronto, Canada. Results indicate that icosapent ethyl (8 g daily for 3 days followed by 4 g daily for 11 days) significantly reduced high-sensitivity C-reactive protein (hs-CRP) and improved symptomatology compared with patients assigned to usual care. Specifically, the primary biomarker endpoint, change in hs-CRP, was significantly reduced by 25% among treated patients (−0.5 mg/L, interquartile range [IQR] [−6.9,0.4], within-group p = 0.011). Conversely, a non-significant 5.6% reduction was observed among usual care patients (−0.1 mg/L, IQR [−3.2,1.7], within-group p = 0.51). An unadjusted between-group primary biomarker analysis was non-significant (p = 0.082). Overall, this report provides evidence of an early anti-inflammatory effect of icosapent ethyl in a modest sample, including an initial well-tolerated loading dose, in symptomatic outpatients with COVID-19. ClinicalTrials.gov Identifier: NCT04412018.

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hs-CRP was significantly reduced within the icosapent ethyl cohort (p value = 0.011)

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Total symptom prevalence was significantly reduced in treatment versus usual care

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Treated participants had significant FLU-PRO score reductions versus usual care

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First evidence of a well-tolerated icosapent ethyl loading dose (8 g/day for 3 days)

Effect of Continuous Electrocardiogram Monitoring on Detection of Undiagnosed Atrial Fibrillation After Hospitalization for Cardiac Surgery: A Randomized Clinical Trial

IMPORTANCE

Postoperative atrial fibrillation (POAF) occurring after cardiac surgery is associated with adverse outcomes. Whether POAF persists beyond discharge is not well defined.

OBJECTIVE

To determine whether continuous cardiac rhythm monitoring enhances detection of POAF among cardiac surgical patients during the first 30 days after hospital discharge compared with usual care.

DESIGN, SETTING, AND PARTICIPANTS

This study is an investigator-initiated, open-label, multicenter, randomized clinical trial conducted at 10 Canadian centers. Enrollment spanned from March 2017 to March 2020, with follow-up through September 11, 2020. As a result of the COVID-19 pandemic, enrollment stopped on July 17, 2020, at which point 85% of the proposed sample size was enrolled. Cardiac surgical patients with CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes, prior stroke or transient ischemic attack, vascular disease, age 65-74 years, female sex) score greater than or equal to 4 or greater than or equal to 2 with risk factors for POAF, no history of preoperative AF, and POAF lasting less than 24 hours during hospitalization were enrolled.

INTERVENTIONS

The intervention group underwent continuous cardiac rhythm monitoring with wearable, patch-based monitors for 30 days after randomization. Monitoring was not mandated in the usual care group within 30 days after randomization.

MAIN OUTCOMES AND MEASURES

The primary outcome was cumulative AF and/or atrial flutter lasting 6 minutes or longer detected by continuous cardiac rhythm monitoring or by a 12-lead electrocardiogram within 30 days of randomization. Prespecified secondary outcomes included cumulative AF lasting 6 hours or longer and 24 hours or longer within 30 days of randomization, death, myocardial infarction, ischemic stroke, non-central nervous system thromboembolism, major bleeding, and oral anticoagulation prescription.

RESULTS

Of the 336 patients randomized (163 patients in the intervention group and 173 patients in the usual care group; mean [SD] age, 67.4 [8.1] years; 73 women [21.7%]; median [interquartile range] CHA2DS2-VASc score, 4.0 [3.0-4.0] points), 307 (91.4%) completed the trial. In the intent-to-treat analysis, the primary end point occurred in 32 patients (19.6%) in the intervention group vs 3 patients (1.7%) in the usual care group (absolute difference, 17.9%; 95% CI, 11.5%-24.3%; P < .001). AF lasting 6 hours or longer was detected in 14 patients (8.6%) in the intervention group vs 0 patients in the usual care group (absolute difference, 8.6%; 95% CI, 4.3%-12.9%; P < .001).

CONCLUSIONS AND RELEVANCE

In post-cardiac surgical patients at high risk of stroke, no preoperative AF history, and AF lasting less than 24 hours during hospitalization, continuous monitoring revealed a significant increase in the rate of POAF after discharge that would otherwise not be detected by usual care. Studies are needed to examine whether these patients will benefit from oral anticoagulation therapy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02793895.

Human cardiac ischemia-reperfusion injury: Blunted stress response with age

BACKGROUND AND AIM

Autophagy is a cytoprotective recycling mechanism, capable of digesting dysfunctional cellular components, and this process is associated with pro-survival outcomes. Autophagy may decline in the aging myocardium, thereby contributing to cardiac dysfunction. However, it remains to be established how autophagy responds to ischemia-reperfusion stress with age.

METHODS

Samples from the right atrium were collected from young (≤50 years; n = 5) and aged (≥70 years; n = 11) patients before and immediately following cardioplegic arrest during coronary artery bypass grafting surgery, a model of human ischemia-reperfusion injury.

RESULTS

Mitochondrial content, as assessed by a cohort of mitochondrial markers, exhibited an overall decrease in the aging myocardium (p = 0.01). In response to IR, COX-I (0.63 vs. 0.91, p = 0.01) increased in young, but not in aged patients (interaction effect p = 0.08). Reductions in LC3-I (0.48 vs. 0.28, p = 0.02) along with declines in TFEB and TFE3 (0.63 vs. 0.20, p = 0.05; 0.71 vs. 0.20, p = 0.01) were observed with age suggesting an impairment in the aged myocardium. Aged patients also displayed an inability to mount an appropriate response to IR compared to their young counterparts, specifically, increases in v-ATPase and NIX (1.06 vs 0.69, p = .01; 1.15 vs 0.69, p = .001) were not seen in the aged.

CONCLUSION

Our data demonstrate a reduced cardiac mitochondrial content and a blunted mitochondrial response to ischemia with age, accompanied by a possible impairment in mitophagy. These findings support an age-associated inability of the atrial myocardium to mount appropriate adaptive responses to stress.

Isolation and characterization of circulating pro-vascular progenitor cell subsets from human whole blood samples

The examination of circulating pro-vascular progenitor cell frequency and function is integral in understanding aberrant blood vessel homeostasis in individuals with cardiometabolic disease. Here, we outline the characterization of progenitor cell subsets from peripheral blood using high aldehyde dehydrogenase (ALDH) activity, an intracellular detoxification enzyme previously associated with pro-vascular progenitor cell status. Using this protocol, cells can be examined by flow cytometry for ALDH activity and lineage restricted cell surface markers simultaneously.

For complete details on the use and execution of this protocol, please refer to Terenzi et al. (2019) and Hess et al. (2019, 2020).

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Aldehyde dehydrogenase is superior in the isolation of progenitor cells

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Flow cytometry is an effective method to characterize pro-vascular cells

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Aggressive gating strategies allows for in-depth progenitor cell characterization

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The use of fresh blood samples will yield most accurate cell prevalence

Loss of endothelial cell-specific autophagy-related protein 7 exacerbates doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) is an effective, broad-spectrum antineoplastic agent with serious cardiotoxic side effects, which may lead to the development of heart failure. Current strategies to diagnose, prevent, and treat DOX-induced cardiotoxicity (DIC) are inadequate. Recent evidence has linked the dysregulation and destruction of the vascular endothelium to the development of DIC. Autophagy is a conserved pro-survival mechanism that recycles and removes damaged sub-cellular components. Autophagy-related protein 7 (ATG7) catalyzes autophagosome formation, a critical step in autophagy. In this study, we used endothelial cell-specific Atg7 knockout (EC-Atg7^−/−) mice to characterize the role of endothelial cell-specific autophagy in DIC. DOX-treated EC-Atg7^−/− mice showed reduced survival and a greater decline in cardiac function compared to wild-type controls. Histological assessments revealed increased cardiac fibrosis in DOX-treated EC-Atg7^−/− mice. Furthermore, DOX-treated EC-Atg7^−/− mice had elevated serum levels of creatine kinase-myocardial band, a biomarker for cardiac damage. Thus, the lack of EC-specific autophagy exacerbated DIC. Future studies on the relationship between EC-specific autophagy and DIC could establish the importance of endothelium protection in preventing DIC.

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Recent data suggest that endothelial cells (ECs) may represent a novel target to reduce doxorubicin (DOX)-linked cardiotoxicity.

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We used EC-specific autophagy-related protein 7 knock-out (EC-Atg7^−/−) mice to determine how ATG7 loss in ECs affects DIC.

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DOX-treated EC-Atg7^−/− mice exhibited reduced survival and cardiac function.

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Cardiac fibrosis and serum creatine kinase-myocardial band levels were increased in DOX-treated EC-Atg7^−/− mice.

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Loss of endothelial Atg7 exacerbated DIC phenotypes.

Empagliflozin Reduces Myocardial Extracellular Volume in Patients With Type 2 Diabetes and Coronary Artery Disease

OBJECTIVES

This study sought to evaluate the effects of empagliflozin on extracellular volume (ECV) in individuals with type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD).

BACKGROUND

Empagliflozin has been shown to reduce left ventricular mass index (LVMi) in patients with T2DM and CAD. The effects on myocardial ECV are unknown.

METHODS

This was a prespecified substudy of the EMPA-HEART (Effects of Empagliflozin on Cardiac Structure in Patients with Type 2 Diabetes) CardioLink-6 trial in which 97 participants were randomized to receive empagliflozin 10 mg daily or placebo for 6 months. Data from 74 participants were included: 39 from the empagliflozin group and 35 from the placebo group. The main outcome was change in left ventricular ECV from baseline to 6 months determined by cardiac magnetic resonance (CMR). Other outcomes included change in LVMi, indexed intracellular compartment volume (iICV) and indexed extracellular compartment volume (iECV), and the fibrosis biomarkers soluble suppressor of tumorgenicity (sST2) and matrix metalloproteinase (MMP)-2.

RESULTS

Baseline ECV was elevated in the empagliflozin group (29.6 ± 4.6%) and placebo group (30.6 ± 4.8%). Six months of empagliflozin therapy reduced ECV compared with placebo (adjusted difference: -1.40%; 95% confidence interval [CI]: -2.60 to -0.14%; p = 0.03). Empagliflozin therapy reduced iECV (adjusted difference: -1.5 ml/m²; 95% CI: -2.6 to -0.5 ml/m²; p = 0.006), with a trend toward reduction in iICV (adjusted difference: -1.7 ml/m²; 95% CI: -3.8 to 0.3 ml/m²; p = 0.09). Empagliflozin had no impact on MMP-2 or sST2.

CONCLUSIONS

In individuals with T2DM and CAD, 6 months of empagliflozin reduced ECV, iECV, and LVMi. No changes in MMP-2 and sST2 were seen. Further investigation into the mechanisms by which empagliflozin causes reverse remodeling is required. (Effects of Empagliflozin on Cardiac Structure in Patients With Type 2 Diabetes [EMPA-HEART]; NCT02998970).

A randomized trial comparing axillary versus innominate artery cannulation for aortic arch surgery

BACKGROUND

Cerebral protection remains the cornerstone of successful aortic surgery; however, there is no consensus as to the optimal strategy.

OBJECTIVE

To compare the safety and efficacy of innominate to axillary artery cannulation for delivering antegrade cerebral protection during proximal aortic arch surgery.

METHODS

This randomized controlled trial (The Aortic Surgery Cerebral Protection Evaluation CardioLink-3 Trial, ClinicalTrials.gov Identifier: NCT02554032), conducted across 6 Canadian centers between January 2015 and June 2018, allocated 111 individuals to innominate or axillary artery cannulation. The primary safety outcome was neuroprotection per the appearance of new severe ischemic lesions on the postoperative diffusion-weighted-magnetic resonance imaging. The primary efficacy outcome was the difference in total operative time. Secondary outcomes included 30-day all-cause mortality and postoperative stroke.

RESULTS

One hundred two individuals (mean age, 63 ± 11 years) were in the primary safety per-protocol analysis. Baseline characteristics between the groups were similar. New severe ischemic lesions occurred in 19 participants (38.8%) in the axillary versus 18 (34%) in the innominate group (P for noninferiority = .0009). Total operative times were comparable (median, 293 minutes; interquartile range, 222-411 minutes) for axillary versus (298 minutes; interquartile range, 231-368 minutes) for innominate (P for superiority = .47). Stroke/transient ischemic attack occurred in 4 (7.1%) participants in the axillary versus 2 (3.6%) in the innominate group (P = .43). Thirty-day mortality, seizures, delirium, and duration of mechanical ventilation were similar in both groups.

CONCLUSIONS

diffusion-weighted magnetic resonance imaging assessments indicate that antegrade cerebral protection with innominate cannulation is safe and affords similar neuroprotection to axillary cannulation during aortic surgery, although the burden of new neurological lesions is high in both groups.

A randomized surgical trial of mitral valve repair with leaflet resection versus leaflet preservation on functional mitral stenosis – primary results of the CAMRA CardioLink-2 trial

Background

The gold standard treatment for mitral valve regurgitation due to prolapse involves surgery with annuloplasty and either leaflet resection or leaflet preservation, with placement of artificial neochordae. It has been suggested that leaflet resection may be prone to functional mitral stenosis, whereby a patient may have a higher mitral gradient at peak exercise compared to a leaflet preservation strategy. Although both techniques are widely used, there has been no prospective randomized study conducted to compare these two techniques, particularly in regard to functional mitral stenosis.

Methods

A total of 104 patients with posterior leaflet prolapse were randomized to undergo mitral repair with either leaflet resection (N=54) or leaflet preservation (N=50) at 7 specialized Canadian cardiac centers. Patient age, proportion of female patients, and mean Society of Thoracic Surgeons risk score was 63.9±10.4 years, 19%, and 1.4% for those who underwent leaflet resection, and 66.3±10.8 years, 16%, and 1.9% for those who underwent leaflet preservation, respectively. The primary endpoint was the mean trans-mitral repair gradient at peak exercise 12-months after repair.

Results

Baseline characteristics were similar between the groups. At 12-months, the mean trans-mitral repair gradient at peak exercise in patients who underwent leaflet resection and preservation was 9.1±5.2 and 8.3±3.3 mmHg (P=0.4), respectively. The two groups had similar mean mitral valve gradient at rest (3.2±1.9 mmHg following resection and 3.1±1.1 mmHg following leaflet preservation, P=0.7). There was no between-group difference for the 6-minute walk distance (451±147 m and 481±95 m for the resection and preservation groups, respectively, P=0.3).

Conclusion

We report the first prospective surgical randomized trial to evaluate commonly used mitral valve repair strategies for posterior leaflet prolapse. Leaflet resection and leaflet preservation both yield acceptable results with no difference in postoperative valve gradient and functional status 12-months after surgical mitral valve repair.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Heart and Stroke Foundation of Canada

Randomized, Controlled Trial Comparing Mitral Valve Repair With Leaflet Resection Versus Leaflet Preservation on Functional Mitral Stenosis

Background:

Equipoise exists between the use of leaflet resection and preservation for surgical repair of mitral regurgitation caused by prolapse. We therefore performed a randomized, controlled trial comparing these 2 techniques, particularly in regard to functional mitral stenosis.

Methods:

One hundred four patients with degenerative mitral regurgitation surgically amenable to either leaflet resection or preservation were randomized at 7 specialized cardiac surgical centers. Exclusion criteria included anterior leaflet or commissural prolapse, as well as a mixed cause for mitral valve disease. Using previous data, we determined that a sample size of 88 subjects would provide 90% power to detect a 5–mm Hg difference in mean mitral valve gradient at peak exercise, assuming an SD of 6.7 mm with a 2-sided test with α=5% and 10% patient attrition. The primary end point was the mean mitral gradient at peak exercise 12 months after repair.

Results:

Patient age, proportion who were female, and Society of Thoracic Surgeons risk score were 63.9±10.4 years, 19%, and 1.4±2.8% for those who were assigned to leaflet resection (n=54), and 66.3±10.8 years, 16%, and 1.9±2.6% for those who underwent leaflet preservation (n=50). There were no perioperative deaths or conversions to replacement. At 12 months, moderate mitral regurgitation was observed in 3 subjects in the leaflet resection group and 2 in the leaflet preservation group. The mean transmitral gradient at 12 months during peak exercise was 9.1±5.2 mm Hg after leaflet resection and 8.3±3.3 mm Hg after leaflet preservation ( P =0.43). The participants had similar resting peak (8.3±4.4 mm Hg versus 8.4±2.6 mm Hg; P =0.96) and mean resting (3.2±1.9 mm Hg versus 3.1±1.1 mm Hg; P =0.67) mitral gradients after leaflet resection and leaflet preservation, respectively. The 6-minute walking distance was 451±147 m for those in the leaflet resection versus 481±95 m for the leaflet preservation group ( P =0.27).

Conclusions:

In this adequately powered randomized trial, repair of mitral prolapse with either leaflet resection or leaflet preservation was associated with similar transmitral gradients at peak exercise at 12 months postoperatively. These data do not support the hypothesis that a strategy of leaflet resection (versus preservation) is associated with a risk of functional mitral stenosis.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier NCT02552771.

Disruption of endothelial cell intraflagellar transport protein 88 exacerbates doxorubicin-induced cardiotoxicity

AIMS

Doxorubicin (DOX) is a potent anticancer drug with severe dose-dependent cardiotoxicity. To address this issue, previous research primarily focused on DOX-induced toxicity on cardiomyocytes. However, more recent research has looked into the endothelium as a therapeutic target due to the emerging role of endothelial cells in the support of cardiomyocyte survival and function.

MAIN METHODS

We investigated a novel role of endothelial cell (EC) primary cilia in the prevention of DOX-mediated cardiotoxicity. Mice lacking EC primary cilia, via the deletion of EC-specific intraflagellar protein 88 (IFT88) expression, were administered DOX (20 mg/kg i.p.), and assessed for survival, cardiac function, cardiac structure changes, and indices of cardiomyocyte injury.

KEY FINDINGS

DOX-treatment resulted in reduced survival and cardiac function (ejection fraction and fractional shortening) in EC-IFT88^-/- mice vs. their similarly treated wild-type littermates. Cardiomyocyte vacuolization, cardiac fibrosis, and serum CK-MB levels were also increased in DOX-treated mice compared to saline-treated controls. However, these parameters were not significantly different when comparing WT and EC-IFT88^-/- mice after DOX treatment.

SIGNIFICANCE

The loss of EC primary cilia accelerated DOX-mediated mortality and reduced cardiac function, suggesting pathways downstream of ciliary-mediated signal transduction as potential targets to promote EC support of cardiomyocyte function during DOX treatment.

Does empagliflozin modulate the autonomic nervous system among individuals with type 2 diabetes and coronary artery disease? The EMPA-HEART CardioLink-6 Holter analysis

Context

We examined if empagliflozin was associated with modulation of cardiac autonomic tone among subjects with type 2 diabetes and stable coronary artery disease (CAD) relative to placebo.

Methods

Using ambulatory 24-h Holter electrocardiographic data prospectively collected from a randomized trial, we compared changes in heart rate variability (HRV) parameters between empagliflozin- and placebo-assigned subjects over a follow-up period of 6 months. Measured HRV domains included: standard deviation (SD) of NN intervals (SDNN), SD of average NN intervals per 5-min (SDANN), root mean square of successive RR interval differences (RMSSD), % successive NN intervals differing >50 ms (ms) (pNN50), low frequency (LF), high frequency (HF) and the LF/HF ratio (LF:HF). Differences in HRV parameters between the 2 groups were compared with analysis of covariance (ANCOVA). Statistical measures of significance were reported as adjusted differences between the 2 groups and their corresponding 95% confidence intervals.

Results

Sixty-six subjects completed 24-h Holter monitoring at baseline and 6-months. Over 6 months, the change in HRV was similar between subjects treated with empagliflozin vs. placebo for the following parameters: RMSSD -1.2 ms (-6.0 to 3.6 ms); pNN50 0.5% (-2.6 to 3.6%); VLF -907.8 ms² (-2388.8 to 573.1 ms²); LF -341 ms² (-878.7 to 196.7 ms²); HF -33.8 ms² (-111.1 to 43.5 ms²); LF:HF -0.1 (-0.4 to 0.2). Subjects who received placebo experienced an increase in SDNN 18.6 ms (2.8–34.3 ms) and SDANN 20.2 ms (3.2–37.3 ms) relative to those treated with empagliflozin.

Conclusion

Compared to placebo, empagliflozin did not result in changes in autonomic tone among individuals with type 2 diabetes and stable coronary artery disease.

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Sodium-glucose cotransporter-2 (SGLT2) inhibitors’ mechanism of cardiovascular benefit is unknown.

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Impaired autonomic tone is associated with adverse cardiac events.

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Cardiac autonomic tone was assessed with Holter studies from a randomized trial.

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Similar autonomic tone noted between subjects treated with empagliflozin and placebo.

Vascular Risk Reduction in Obesity through Reduced Granulocyte Burden and Improved Angiogenic Monocyte Content following Bariatric Surgery

Bariatric surgery, in addition to the benefit of sustained weight loss, can also reduce cardiometabolic risk and mortality. Lifelong vessel maintenance is integral to the prevention of cardiovascular disease. Using aldehyde dehydrogenase activity, an intracellular detoxifying enzyme present at high levels within pro-vascular progenitor cells, we observed an association between chronic obesity and “regenerative cell exhaustion” (RCE), a pathology whereby chronic assault on circulating regenerative cell types can result in adverse inflammation and diminished vessel repair. We also describe that, at 3 months following bariatric surgery, systemic inflammatory burden was reduced and pro-angiogenic macrophage precursor content was improved in subjects with severe obesity, suggesting the restoration of a microenvironment to support vessel homeostasis. These data suggest that bariatric surgery may reverse deleterious events that predispose patients with morbid obesity to cardiovascular risk.

Obesity features a low frequency of ALDH and CD133 co-expressing cells

Bariatric surgery results in lower granulocyte precursors expressing ALDH

Macrophage balance favors M2 polarization following bariatric surgery

Cellular changes after bariatric surgery give insight into reducing CV risk