Prognostic value of cardiovascular magnetic resonance left ventricular volumetry and geometry in patients receiving an implantable cardioverter defibrillator

BACKGROUND

Current indications for implantable cardioverter defibrillator (ICD) implantation for sudden cardiac death prevention rely primarily on left ventricular (LV) ejection fraction (LVEF). Currently, two different contouring methods by cardiovascular magnetic resonance (CMR) are used for LVEF calculation. We evaluated the comparative prognostic value of these two methods in the ICD population, and if measures of LV geometry added predictive value.

METHODS

In this retrospective, 2-center observational cohort study, patients underwent CMR prior to ICD implantation for primary or secondary prevention from January 2005 to December 2018. Two readers, blinded to all clinical and outcome data assessed CMR studies by: (a) including the LV trabeculae and papillary muscles (TPM) (trabeculated endocardial contours), and (b) excluding LV TPM (rounded endocardial contours) from the total LV mass for calculation of LVEF, LV volumes and mass. LV sphericity and sphere-volume indices were also calculated. The primary outcome was a composite of appropriate ICD shocks or death.

RESULTS

Of the 372 consecutive eligible patients, 129 patients (34.7%) had appropriate ICD shock, and 65 (17.5%) died over a median duration follow-up of 61 months (IQR 38-103). LVEF was higher when including TPM versus excluding TPM (36% vs. 31%, p < 0.001). The rate of appropriate ICD shock or all-cause death was higher among patients with lower LVEF both including and excluding TPM (p for trend = 0.019 and 0.004, respectively). In multivariable models adjusting for age, primary prevention, ischemic heart disease and late gadolinium enhancement, both LVEF (HR per 10% including TPM 0.814 [95%CI 0.688-0.962] p = 0.016, vs. HR per 10% excluding TPM 0.780 [95%CI 0.639-0.951] p = 0.014) and LV mass index (HR per 10 g/m2 including TPM 1.099 [95%CI 1.027-1.175] p = 0.006; HR per 10 g/m2 excluding TPM 1.126 [95%CI 1.032-1.228] p = 0.008) had independent prognostic value. Higher LV end-systolic volumes and LV sphericity were significantly associated with increased mortality but showed no added prognostic value.

CONCLUSION

Both CMR post-processing methods showed similar prognostic value and can be used for LVEF assessment. LVEF and indexed LV mass are independent predictors for appropriate ICD shocks and all-cause mortality in the ICD population.

Contemporary use of guideline-based higher potency P2Y12 receptor inhibitor therapy in patients with moderate-to-high risk non-ST-segment elevation myocardial infarction: Results from the Canadian ACS reflective II cross-sectional study

Background

After myocardial infarction, guidelines recommend higher‐potency P2Y12 receptor inhibitors, namely ticagrelor and prasugrel, over clopidogrel.

Hypothesis

We aimed to determine the contemporary use of higher‐potency antiplatelet therapy in Canadian patients with non‐ST‐elevation myocardial infarction (NSTEMI).

Methods

A total of 684 moderate‐to‐high risk NSTEMI patients were enrolled in the prospective Canadian ACS Reflective II registry at 12 Canadian hospitals and three clinics in five provinces between July 2016 and May 2018. Multivariable logistic regression modeling was performed to assess factors independently associated with higher‐potency P2Y12 receptor inhibitor use at discharge.

Results

At hospital discharge, 78.3% of patients were treated with a P2Y12 receptor inhibitor. Among patients discharged on a P2Y12 receptor inhibitor, use of higher‐potency P2Y12 receptor inhibitor was 61.4%. After adjustment, treatment in‐hospital with PCI (OR 4.48, 95%CI 3.34–6.03, p < .0001) was most strongly associated with higher use of higher‐potency P2Y12 receptor inhibitor, while oral anticoagulant use at discharge (OR 0.03, 95%CI 0.01–0.12, p < .0001), and atrial fibrillation (OR 0.40, 95%CI 0.17–0.98, p = .046) were most strongly associated with lower use of higher‐potency P2Y12 receptor inhibitor. Use of higher‐potency P2Y12 receptor inhibitor varied across provinces (range, 21.6%–78.9%).

Discussion

In contemporary Canadian practice, approximately 60% of moderate‐to‐high risk NSTEMI patients discharged on a P2Y12 receptor inhibitor are treated with a higher‐potency P2Y12 receptor inhibitor. In addition to factors that increase risk of bleeding, interprovincial differences in practice patterns were associated with use of higher‐potency P2Y12 receptor inhibitor at discharge. Opportunities remain for further optimization of evidence‐based, guideline‐recommended antiplatelet therapy use.

Clinical risk prediction models for the prognosis and management of acute coronary syndromes

Patients with acute coronary syndromes (ACS), particularly non-ST-segment elevation ACS, represent a spectrum of patients at variable risk of short- and long-term adverse clinical outcomes. Accurate prognostic assessment in this population requires the simultaneous consideration of multiple clinical and laboratory variables which may be under-recognized by the treating physicians, leading to an observed risk-treatment paradox in the use of invasive and pharmacological therapies. The routine application of established clinical risk scores, such as the Global Registry of Acute Coronary Events risk score, is recommended by major international clinical practice guidelines for structured risk stratification at the time of presentation, but uptake remains inconsistent. This article discusses the methodology of designing, deriving, and validating clinical risk scores, reviews the major validated risk scores for assessing prognosis in ACS, and examines their role in guiding clinical decision-making in ACS management, especially the timing of invasive coronary angiography. We also discuss emerging data on the impact of the routine use of such risk scores on patient management and clinical outcomes, as well as future directions for investigation in this field.

The effects of saxagliptin on cardiac structure and function using cardiac MRI (SCARF)

PURPOSE

A recent large cardiovascular outcome trial in patients with type 2 diabetes (T2DM) demonstrated excess heart failure hospitalization with saxagliptin. We sought to evaluate the impact of saxagliptin on cardiac structure and function using cardiac magnetic resonance imaging (CMR) in patients with T2DM without pre-existing heart failure.

METHODS

In this prospective study, patients with T2DM without heart failure were prescribed saxagliptin as part of routine guideline-directed management. Clinical assessment, CMR imaging and biomarkers were assessed in a blinded fashion and compared following 6 months of continued treatment. The primary outcome was the change in left ventricular (LV) ejection fraction (LVEF) after 6 months of therapy. Key secondary outcomes included changes in LV and right ventricular (RV) end-diastolic volume, ventricular mass, LV global strain and cardiac biomarkers [N terminal pro B-type natriuretic peptide (NT-proBNP) and high sensitivity C-reactive protein (hsCRP)] over 6 months.

RESULTS

The cohort (n = 16) had a mean age of 59.9 years with 69% being male. The mean hemoglobin A1c (HbA1c) was 8.3%. Mean baseline LVEF was 57% ± 3.4, with no significant change over 6 months (- 0.2%, 95% CI - 2.5, 2.1, p = 0.86). Detailed CMR analyses that included LV/RV volumes, LV mass, and feature tracking-derived strain showed no significant change (all p > 0.50). NT-proBNP and hsCRP levels did not significantly change (p > 0.20).

CONCLUSIONS

In this cohort of stable ambulatory patients with T2DM without heart failure, saxagliptin treatment was not associated with adverse ventricular remodeling over 6 months as assessed using CMR and biomarkers.

Left Ventricular Fibrosis in Middle-Age Athletes and Physically Active Adults

INTRODUCTION

Cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) and T1 mapping techniques enable the quantification of focal and diffuse myocardial LGE, respectively. Studies have shown evidence of fibrosis in middle-age athletes, but not relative to physically active (PA) adults who perform recommended physical activity levels. Therefore, we examined cardiac remodeling and presence of left ventricular (LV) LGE and T1 values in both recreational middle-age endurance athletes (EA) and PA adults.

METHODS

Healthy EA and PA adults (45-65 yr) completed a standardized 3-T CMR protocol with ventricular volumetry, LV LGE, and T1 mapping.

RESULTS

Seventy-two EA and 20 PA participants (mean age, 53 ± 5 vs 56 ± 4 yr; P < 0.01; V˙O2peak = 50 ± 7 vs 37 ± 9 mL·kg·min, P < 0.0001) were examined, with CMR data available in 89/92 participants. Focal LV LGE was observed in 30% of participants (n = 27/89): 33% of EA (n = 23/69; 33%) and 20% of PA (n = 4/20; 20%). LGE was present at the right ventricular hinge point (n = 21/89; 23.5%) or identified as ischemic (n = 2/89; 2%) or nonischemic (n = 4/89; 4%). Focal LV LGE was observed similarly in both EA and PA (P = 0.25). EA had larger LV chamber sizes and T1 native values (1169 ± 35 vs 1190 ± 26, P = 0.02) compared with PA, with similar LV ejection fraction. Global extracellular volume (ECV) was similar in both EA and PA (22.6% ± 3.5% vs 21.5% ± 2.6%, P = 0.26), with no relationship between global ECV and LV mass (r = -0.16, P = 0.19).

CONCLUSIONS

Focal LGE at the right ventricular hinge point was detected at the same frequency in both groups, was unrelated to demographic or clinical indices, and was found without evidence of global ECV expansion in EA, suggesting a physiologic remodeling response. The long-term clinical implications of hinge-point LGE require clarification using prospective, long-term follow-up studies.

Lipid Testing, Lipid-Modifying Therapy, and PCSK9 (Proprotein Convertase Subtilisin-Kexin Type 9) Inhibitor Eligibility in 27 979 Patients With Incident Acute Coronary Syndrome

BACKGROUND

While registry-based studies have shown that as many as 1 in 2 patients with stable atherosclerotic cardiovascular disease would be eligible for PCSK9i (proprotein convertase subtilisin-kexin type 9 inhibitor) therapy, this has not been studied in a large population-based postacute coronary syndrome (ACS) cohort.

METHODS

We examined lipid testing performed in hospital or within 90 days of discharge and lipid-lowering therapies dispensed within 90 days of discharge in patients surviving for at least 1 year after their first ACS between 2012 and 2018 in the province of Alberta, Canada. We estimated the proportion of patients eligible for PCSK9i and the expected benefits of treatment.

RESULTS

Of the 27 979 patients (median age 64.0 years, 29.3% female, 28.0% diabetic), 3750 (13.4%) did not have lipid testing in-hospital or within 90 days postdischarge. Untested patients were more likely to be older, female, from rural areas, to have more comorbidities, to already be on cardioprotective therapies, to present with unstable angina, and were less likely to have invasive interventions (all P<0.0001). Of the 24 229 tested, 18 767 (77.5%) had at least one lipid value above guideline-recommended threshold (LDL [low-density lipoprotein] ≥1.8 mmol/L [70 mg/dL] and non-HDL [high-density lipoprotein] ≥2.6 mmol/L [100 mg/dL]), of which 7284 (38.8%) did not have repeat testing within the year after discharge. Lipid testing in hospital was associated with higher rates of initiation or escalation of statin therapy within 90 days of their ACS (adjusted odds ratio, 2.13 [95% CI, 1.97-2.30). In total, 9592 patients (39.6% of the tested cohort) would be eligible for PCSK9i use, which could result in 184 fewer cardiovascular events over 3.4 years, including cardiovascular death, nonfatal ACS (myocardial infarction or unstable angina requiring hospitalization), and ischemic stroke.

CONCLUSIONS

Within 90 days of incident ACS, ≈80% of patients did not meet guideline-recommended lipid thresholds and more than one-third would potentially be eligible for PCSK9i.

Left atrial volume and function measured by cardiac magnetic resonance imaging as predictors of shocks and mortality in patients with implantable cardioverter-defibrillators

Left atrial (LA) volume and function (LA ejection fraction, LAEF) have demonstrated prognostic value in various cardiovascular diseases. We investigated the incremental value of LA volume and LAEF as measured by cardiovascular magnetic resonance imaging (CMR) for prediction of appropriate implantable cardioverter defibrillator (ICD) shock or all-cause mortality, in patients with ICD. We conducted a retrospective, multi-centre observational cohort study of patients who underwent CMR prior to primary or secondary prevention ICD implantation. A single, blinded reader measured maximum LA volume index (maxLAVi), minimum LA volume index (minLAVi), and LAEF. The primary outcome was a composite of independently adjudicated appropriate ICD shock or all-cause death. A total of 392 patients were enrolled. During a median follow-up time of 61 months, 140 (35.7%) experienced an appropriate ICD shock or died. Higher maxLAVi and minLAVi, and lower LAEF were associated with greater risk of appropriate ICD shock or death in univariate analysis. However, in multivariable analysis, LAEF (HR 0.92 per 10% higher, 95% CI 0.81-1.04, p = 0.17) and maxLAVi (HR 1.02 per 10 ml/m² higher, 95% CI 0.93-1.12, p = 0.72) were not independent predictors of the primary outcome. In conclusion, LA volume and function measured by CMR were univariate but not independent predictors of appropriate ICD shocks or mortality. These findings do not support the routine assessment of LA volume and function to refine risk stratification to guide ICD implant. Larger studies with longer follow-up are required to further delineate the clinical implications of LA size and function.

Objective Risk Assessment vs Standard Care for Acute Coronary Syndromes: A Randomized Clinical Trial

Importance

Although international guidelines recommend use of the Global Registries of Acute Coronary Events (GRACE) risk score (GRS) to guide acute coronary syndrome (ACS) treatment decisions, the prospective utility of the GRS in improving care and outcomes is unproven.

Objective

To assess the effect of routine GRS implementation on guideline-indicated treatments and clinical outcomes of hospitalized patients with ACS.

Design, Setting, and Participants

Prospective cluster (hospital-level) randomized open-label blinded end point (PROBE) clinical trial using a multicenter ACS registry of acute care cardiology services. Fixed sampling of the first 10 patients within calendar month, with either ST-segment elevation or non-ST-segment elevation ACS. The study enrolled patients from June 2014 to March 2018, and data were analyzed between February 2020 and April 2020.

Interventions

Implementation of routine risk stratification using the GRS and guideline recommendations.

Main Outcomes and Measures

The primary outcome was a performance score based on receipt of early invasive treatment, discharge prescription of 4 of 5 guideline-recommended pharmacotherapies, and cardiac rehabilitation referral. Clinical outcomes included a composite of all-cause death and/or myocardial infarction (MI) within 1 year.

Results

This study enrolled 2318 patients from 24 hospitals and was stopped prematurely owing to futility. Of the patients enrolled, median age was 65 years (interquartile range, 56-74 years), 29.5% were women (n = 684), and 62.9% were considered high risk (n = 1433). Provision of all 3 measures among high-risk patients did not differ between the randomized arms (GRS: 424 of 717 [59.9%] vs control: 376 of 681 [55.2%]; odds ratio [OR], 1.04; 95% CI, 0.63-1.71; P = .88). The provision of early invasive treatment was increased compared with the control arm (GRS: 1042 of 1135 [91.8%] vs control: 989 of 1183 [83.6%]; OR, 2.26; 95% CI, 1.30-3.96; P = .004). Prescription of 4 of 5 guideline-recommended pharmacotherapies (GRS: 864 of 1135 [76.7%] vs control: 893 of 1183 [77.5%]; OR, 0.97; 95% CI, 0.68-1.38) and cardiac rehabilitation (GRS: 855 of 1135 [75.1%] vs control: 861 of 1183 [72.8%]; OR, 0.68; 95% CI, 0.32-1.44) were not different. By 12 months, GRS intervention was not associated with a significant reduction in death or MI compared with the control group (GRS: 96 of 1044 [9.2%] vs control: 146 of 1087 [13.4%]; OR, 0.66; 95% CI, 0.38-1.14).

Conclusions and Relevance

Routine GRS implementation in cardiology services with high levels of clinical care was associated with an increase in early invasive treatment but not other aspects of care. Low event rates and premature study discontinuation indicates the need for further, larger scale randomized studies.

Trial Registration

anzctr.org.au Identifier: ACTRN12614000550606.

Awareness of Warning Symptoms of Heart Disease and Stroke: Results of a Follow-up Study of the Chinese Canadian Cardiovascular Health Project

Background

Our original pilot study in 2008 demonstrated a poor degree of awareness of heart disease and stroke among Chinese Canadians, warranting an updated survey of their knowledge. We sought to determine the current degree of knowledge of cardiovascular disease, including stroke, among ethnic Chinese residents of Canada.

Methods

A 35-question online survey was conducted in the fall of 2017 among 1001 Chinese Canadians (aged ≥ 18 years) in the greater Toronto area (n = 501) and Vancouver (n = 500). Knowledge of heart disease and stroke, such as signs and symptoms of stroke and heart attack, health habits, and initial response to a cardiovascular emergency were assessed.

Results

A total of 52.0% of the respondents were female, and 46.3% were aged <45 years. A total of 40.1% spoke Cantonese, and 23.7% spoke Mandarin; 79.5% were immigrants, and 31% had lived in Canada < 10 years. A total of 85% identified at least one heart attack symptom, and 80% identified at least one stroke symptom; 86.2% indicated that they would call 911 if experiencing a heart attack or stroke. Internet use was positively associated with the ability to identify a greater number of heart attack and stroke symptoms, compared to the number among non–Internet users (P < 0.001). Women were 14% more likely to overlook gender as a risk factor for cardiovascular disease (CVD).

Conclusions

This study found that in 2017, compared to 2008, awareness of symptoms of heart disease and stroke improved among Chinese Canadians residing in Toronto and Vancouver.

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).

Serial Cardiovascular Magnetic Resonance Strain Measurements to Identify Cardiotoxicity in Breast Cancer: Comparison With Echocardiography

OBJECTIVES

This study sought to compare the prognostic value of cardiovascular magnetic resonance (CMR) and 2-dimensional echocardiography (2DE) derived left ventricular (LV) strain, volumes, and ejection fraction for cancer therapy-related cardiac dysfunction (CTRCD) in women with early stage breast cancer.

BACKGROUND

There are limited comparative data on the association of CMR and 2DE derived strain, volumes, and LVEF with CTRCD.

METHODS

A total of 125 prospectively recruited women with HER2+ early stage breast cancer receiving sequential anthracycline/trastuzumab underwent 5 serial CMR and 6 of 2DE studies before and during treatment. CMR LV volumes, left ventricular ejection fraction tagged-CMR, and feature-tracking (FT) derived global systolic longitudinal (GLS) and global circumferential strain (GCS) and 2DE-based LV volumes, function, GLS, and GCS were measured. CTRCD was defined by the cardiac review and evaluation committee criteria.

RESULTS

Twenty-eight percent of patients developed CTRCD by CMR and 22% by 2DE. A 15% relative reduction in 2DE-GLS increased the CTRCD odds by 133% at subsequent follow-up, compared with 47%/50% by tagged-CMR GLS/GCS and 87% by FT-GCS. CMR and 2DE-LVEF and indexed left ventricular end-systolic volume (LVESVi) were also associated with subsequent CTRCD. The prognostic threshold change in CMR-left ventricular ejection fraction and FT strain for subsequent CTRCD was similar to the known minimum-detectable difference for these measures, whereas for tagged-CMR strain it was lower than the minimum-detectable difference; for 2DE, only the prognostic threshold for GLS was greater than the minimum-detectable difference. Of all strain methods, 2DE-GLS provided the highest increase in discriminatory value over baseline clinical risk factors for subsequent CTRCD. The combination of 2DE-left ventricular ejection fraction or LVESVi and strain provided greater increase in the area under the curve for subsequent CTRCD over clinical risk factors than CMR left ventricular ejection fraction or LVESVi and strain (18% to 22% vs. 9% to 14%).

CONCLUSIONS

In women with HER2+ early stage breast cancer, changes in CMR and 2DE strain, left ventricular ejection fraction, and LVESVi were prognostic for subsequent CTRCD. When LVEF can be measured precisely by CMR, FT strain may function as an additional confirmatory prognostic measure, but with 2DE, GLS is the optimal prognostic measure. (Evaluation of Myocardial Changes During BReast Adenocarcinoma Therapy to Detect Cardiotoxicity Earlier With MRI [EMBRACE-MRI]; NCT02306538).

Cardiac remodeling in middle-aged endurance athletes: relation between signal-averaged electrocardiogram and LV mass

The relationship between structural and electrical remodeling in the heart, particularly after long-standing endurance training, remains unclear. Signal-averaged electrocardiogram (SAECG) may provide a more sensitive method to evaluate cardiac remodeling than a 12-lead electrocardiogram (ECG). Accurate measures of electrical function (SAECG filtered QRS duration (fQRSd) and late potentials (LP) and left-ventricular (LV) mass (cardiac magnetic resonance, CMR) can allow an assessment of structural remodeling and QRS prolongation. Endurance athletes (45-65 yr old, >10 yr of endurance sport), screened to exclude cardiac disease, had standardized 12-lead ECG, SAECG, resting echocardiogram (ECHO), and CMR performed. SAECG fQRSd was correlated with QRS duration on the 12-lead ECG, and ECHO and CMR-derived LV mass. Participants (n = 82, 67% male, mean age: 54 ± 6 yr, mean V̇o_2max: 50 ± 7 mL/kg/min) had a CMR-derived LV mass of 118 ± 28 g/m² and a fQRSd of 112 ± 8 ms (46% had abnormal fQRSd (>114 ms), and 51% met clinical threshold for abnormal SAECG). fQRSd was positively correlated with the 12-lead ECG QRS duration (r = 0.83), ECHO-derived LV mass (r = 0.60), CMR-derived LV mass (r = 0.58) and LV end-diastolic volume (r = 0.63, P < 0.001 for all). fQRSd had higher correlations with ECHO and CMR-derived LV mass than 12-lead ECG (P < 0.0008 and P < 0.0005, respectively). In conclusion, in a healthy cohort of middle-aged endurance athletes, the SAECG is often abnormal by conventional criteria, and is correlated with structural remodeling, but CMR evaluation does not indicate pathologic structural remodeling. SAECG fQRSd is superior to the 12-lead ECG for the electrocardiographic evaluation of LV mass.NEW & NOTEWORTHY Study findings indicate that a positive correlation exists between electrical (SAECG fQRSd) and structural indices (LV mass) in middle-aged endurance athletes with normal physiological LV adaptation, in the absence of known cardiac pathology. SAECG fQRSd may also provide an alternative, superior method for identifying increased LV mass compared to other 12-lead ECG criteria.

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.

•

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

•

Impaired autonomic tone is associated with adverse cardiac events.

•

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

•

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

Cardiac magnetic resonance for asymptomatic patients with type 2 diabetes and cardiovascular high risk (CATCH): a pilot study

Background

Stress cardiovascular magnetic resonance (CMR) to screen for silent myocardial ischaemia in asymptomatic high risk patients with type 2 diabetes mellitus (DM) has never been performed, and its effectiveness is unknown. Our aim was to determine the feasibility of a screening programme using stress CMR by obtaining preliminary data on the prevalence of silent ischaemia caused by obstructive coronary artery disease (CAD) and quantify myocardial perfusion in asymptomatic high risk patients with type 2 diabetes.

Methods

In this prospective cohort study, we recruited 63 asymptomatic DM patients (mean age 66 years ± 4.4 years; 77.8% male); with Framingham risk score ≥ 20% from 3 sites from June 2017 to August 2018. Normal volunteers were recruited to determine normal global myocardial perfusion reserve index (MPRI). Adenosine stress CMR and global MPRI was performed and measured in all subjects. Positive stress CMR cases were referred for catheter coronary angiography (CCA) with/without fractional flow reserve (FFR) measurements. Positive CCA was defined as an FFR ≤ 0.8 or coronary narrowing ≥ 70%. Patients were followed up for major adverse cardiovascular events. Prevalence is presented as patient numbers and percentage. Mann–Whitney U test was used to compare global MPRI between patients and normal volunteers.

Results

13 patients had positive stress CMR with positive CCA (20.6% of patient population), while 9 patients with positive stress CMR examinations had a negative CCA. 5 patients (7.9%) had infarcts detected of which 2 patients had no stress perfusion defects. 12 patients had coronary artery stents inserted, whilst 1 patient declined stent placement. DM patients had lower global MPRI than normal volunteers (n = 7) (1.43 ± 0.27 vs 1.83 ± 0.31 respectively; p < 0.01). After a median follow-up of 653 days, there was no death, heart failure, acute coronary syndrome hospitalisation or stroke.

Conclusion

20.6% of asymptomatic DM patients (with Framingham risk ≥ 20%) had silent obstructive CAD. Furthermore, asymptomatic patients have reduced global MPRI than normal volunteers.

Trial Registration: ClinicalTrials.gov Registration Number: NCT03263728 on 28th August 2017; https://clinicaltrials.gov/ct2/show/NCT03263728.

Comparison of outcomes in a population-based cohort of metastatic breast cancer patients receiving anti-HER2 therapy with clinical trial outcomes

PURPOSE

Little data exist for comparing cardiac safety and survival outcomes of trastuzumab/pertuzumab or ado-T emtansine (TDM1) in metastatic breast cancer (MBC) patients enrolled in randomized clinical trial (RCT) vs the real-world.

METHODS

This was a retrospective population-based cohort of all patients with MBC treated with trastuzumab/pertuzumab or TDM1 (2012-2017) in Ontario, Canada. Outcomes were incident heart failure (HF) and overall survival (OS). RCT data were obtained from digitizing survival curves and compared with cohort data using Kaplan-Meier analysis. Age-based comparison of outcomes was conducted for patients ≥ 65 years old vs younger than 65.

RESULTS

The two cohorts composed of 833 and 397 patients treated with trastuzumab/pertuzumab and TDM1, of whom 5.5% and 7.6% had baseline HF, respectively. Incident HF following trastuzumab/pertuzumab or TDM1 was low (trastuzumab/pertuzumab 1.8 events/100 person years; TDM1 0.02 events/100 person years). The median OS was 39.2 and 56.4 months in the trastuzumab/pertuzumab population-based cohort and CLEOPATRA, respectively. The median OS was 15.4 and 30.9 months in the TDM1 population-based cohort and EMILIA, respectively. Cohort OS was significantly worse than RCT OS (trastuzumab/pertuzumab HR 1.67, 95% CI 1.37-2.03, p < 0.0001; TDM1 HR 2.80, 95% CI 2.27-3.44, p < 0.0001). Older patients had worse OS than younger patients for trastuzumab/pertuzumab (HR 1.60, 95% CI 1.19-2.16, p = 0.0018), but not for TDM1 (HR 1.16, 95% CI 0.81-1.66, p = 0.43).

CONCLUSION

HF incidence during trastuzumab/pertuzumab or TDM1 therapy in this real-world cohort was low. Survival in this cohort was worse compared to RCT, suggesting that recruitment of patients similar to the real-world population is required.

Guideline-indicated treatments and diagnostics, GRACE risk score, and survival for non-ST elevation myocardial infarction

Aims

To investigate whether improved survival from non-ST-elevation myocardial infarction (NSTEMI), according to GRACE risk score, was associated with guideline-indicated treatments and diagnostics, and persisted after hospital discharge.

Methods and results

National cohort study (n = 389 507 patients, n = 232 hospitals, MINAP registry), 2003–2013. The primary outcome was adjusted all-cause survival estimated using flexible parametric survival modelling with time-varying covariates. Optimal care was defined as the receipt of all eligible treatments and was inversely related to risk status (defined by the GRACE risk score): 25.6% in low, 18.6% in intermediate, and 11.5% in high-risk NSTEMI. At 30 days, the use of optimal care was associated with improved survival among high [adjusted hazard ratio (aHR) −0.66 95% confidence interval (CI) 0.53–0.86, difference in absolute mortality rate (AMR) per 100 patients (AMR/100–0.19 95% CI −0.29 to −0.08)], and intermediate (aHR = 0.74, 95% CI 0.62–0.92; AMR/100 = −0.15, 95% CI −0.23 to −0.08) risk NSTEMI. At the end of follow-up (8.4 years, median 2.3 years), the significant association between the use of all eligible guideline-indicated treatments and improved survival remained only for high-risk NSTEMI (aHR = 0.66, 95% CI 0.50–0.96; AMR/100 = −0.03, 95% CI −0.06 to −0.01). For low-risk NSTEMI, there was no association between the use of optimal care and improved survival at 30 days (aHR = 0.92, 95% CI 0.69–1.38) and at 8.4 years (aHR = 0.71, 95% CI 0.39–3.74).

Conclusion

Optimal use of guideline-indicated care for NSTEMI was associated with greater survival gains with increasing GRACE risk, but its use decreased with increasing GRACE risk.

Thiamin supplementation does not improve left ventricular ejection fraction in ambulatory heart failure patients: a randomized controlled trial

BACKGROUND

Thiamin, a water-soluble B-complex vitamin, functions as a coenzyme in macronutrient oxidation and in the production of cellular ATP. Data suggest that thiamin depletion occurs in heart failure (HF). Therefore, thiamin supplementation in HF patients may improve cardiac function.

OBJECTIVE

We sought to determine whether oral thiamin supplementation improves left ventricular ejection fraction (LVEF), exercise tolerance, and quality of life among patients with HF and reduced LVEF.

METHODS

In this prospective, multicenter, double-blind, placebo-controlled randomized trial, eligible ambulatory patients with HF and reduced LVEF were recruited from 4 academic and community hospitals between 2010 and 2015. Participants were randomly assigned to receive either 200 mg oral thiamin mononitrate per day or placebo for 6 mo.

RESULTS

Sixty-nine patients (mean ± SD age: 64 ± 12 y; 83% men; LVEF: 37% ± 11%) were randomly assigned: 34 received placebo and 35 received thiamin supplementation. Erythrocyte thiamin pyrophosphate and urine thiamin concentrations were significantly higher in the supplemented group than in the placebo group at 6 mo (P = 0.02 and <0.001, respectively). At 6 mo, LVEF was significantly higher in the placebo group than in the thiamin group (38%; 95% CI: 36%, 39% compared with 35%; 95% CI: 33%, 37%, P = 0.047) after adjusting for baseline measurements. There were no significant differences in Minnesota Living with Heart Failure score, distance walked in 6 min, and N-terminal prohormone of brain natriuretic peptide concentrations between the 2 groups. One patient (2.9%) in the thiamin-supplemented group and none in the control group died at 6 mo.

CONCLUSIONS

In ambulatory patients with HF and reduced LVEF, thiamin supplementation for 6 mo did not improve LVEF, quality of life, or exercise capacity, despite increases in thiamin concentrations. These findings do not support routine thiamin supplementation in the treatment of HF and reduced LVEF.This trial was registered at clinicaltrials.gov as NCT00959075.

Cardiac MRI measurements of pericardial adipose tissue volumes in patients on in-centre nocturnal hemodialysis

BACKGROUND

Conversion from conventional hemodialysis (CHD) to in-centre nocturnal hemodialysis (INHD) is associated with left ventricular (LV) mass regression, but the underlying mechanisms are not fully understood. Using cardiac MRI (CMR), we examined the effects of INHD on epicardial adipose tissue (EAT) and paracardial adipose tissue (PAT), and the relationships between EAT, PAT and LV remodeling, biomarkers of nutrition, myocardial injury, fibrosis and volume.

METHODS

We conducted a prospective multicenter cohort study of 37 patients transitioned from CHD to INHD and 30 patients on CHD (control). Biochemical markers and CMR were performed at baseline and 52 weeks. CMR images were analyzed by independent readers, blinded to order and treatment group.

RESULTS

Among 64 participants with complete CMR studies at baseline (mean age 54; 43% women), there were no significant differences in EAT index (60.6 ± 4.3 mL/m² vs 64.2 ± 5.1 mL/m², p = 0.99) or PAT index (60.0 ± 5.4 mL/m² vs 53.2 ± 5.9 mL/m², p = 0.42) between INHD and CHD groups. Over 52 weeks, EAT index and PAT index did not change significantly in INHD and CHD groups (p = 0.21 and 0.14, respectively), and the changes in EAT index and PAT index did not differ significantly between INHD and CHD groups (p = 0.30 and 0.16, respectively). Overall, changes in EAT index inversely correlated with changes in LV end-systolic volume index (LVESVI) but not LV end-diastolic volume index (LVEDVI), LV mass index (LVMI), and LV ejection fraction (LVEF). Changes in PAT index inversely correlated with changes in LVESVI, LVMI and positively correlated with changes in LVEF. There were no correlations between changes in EAT index or PAT index with changes in albumin, LDL, triglycerides, troponin-I, FGF-23, or NT-proBNP levels over 52 weeks (all p > 0.30).

CONCLUSIONS

INHD was not associated with any changes in EAT index and PAT index over 12 months. Changes in EAT index were not significantly associated with changes in markers of LV remodeling, nutrition, myocardial injury, fibrosis, volume status. In contrast, changes in PAT index, which paradoxically is expected to exert less paracrine effect on the myocardium, were correlated with changes in LVESVI, LVMI and LVEF. Larger and longer-term studies may clarify the role of PAT in cardiac remodeling with intensified hemodialysis. CLINICALTRIALS.

GOV IDENTIFIER

NCT00718848.

Frailty and Outcomes After Myocardial Infarction: Insights From the CONCORDANCE Registry

Background

Little is known about the prognostic implications of frailty, a state of susceptibility to stressors and poor recovery to homeostasis in older people, after myocardial infarction (MI).

Methods and Results

We studied 3944 MI patients aged ≥65 years treated at 41 Australian hospitals from 2009 to 2016 in the CONCORDANCE (Australian Cooperative National Registry of Acute Coronary Care, Guideline Adherence and Clinical Events) registry. Frailty index (FI) was determined using the health deficit accumulation method. All‐cause and cardiac‐specific mortality at 6 months were compared between frail (FI >0.25) and nonfrail (FI ≤0.25) patients. Among 1275 patients with ST‐segment–elevation MI (STEMI), 192 (15%) were frail, and among 2669 non‐STEMI (NSTEMI) patients, 902 (34%) were frail. Compared with nonfrail counterparts, frail STEMI patients received 30% less reperfusion therapy and 22% less revascularization during index hospitalization; frail NSTEMI patients received 30% less diagnostic angiography and 39% less revascularization. Unadjusted 6‐month all‐cause mortality (STEMI: 13% versus 3%; NSTEMI: 13% versus 4%) and cardiac‐specific mortality (STEMI: 6% versus 1.4%, NSTEMI: 3.2% versus 1.2%) were higher among frail patients. After adjustment for known prognosticators, FI was significantly associated with higher 6‐month all‐cause (STEMI: odds ratio: 1.74 per 0.1 FI [95% confidence interval, 1.37–2.22], P<0.001; NSTEMI: odds ratio: 1.62 per 0.1 FI [95% confidence interval, 1.40–1.87], P<0.001) but not cardiac‐specific mortality (STEMI: P=0.99; NSTEMI: P=0.93).

Conclusions

Frail patients receive lower rates of invasive cardiac care during MI hospitalization. Increased frailty was independently associated with increased postdischarge all‐cause mortality but not cardiac‐specific mortality. These findings inform identification of frailty during MI hospitalization as a potential opportunity to address competing risks for mortality in this high‐risk population.