Electrical synchronization achieved by multipoint pacing combined with dynamic atrioventricular delay.

PURPOSE: Multipoint pacing (MPP) improves left ventricular (LV) electrical synchrony in cardiac resynchronization therapy (CRT). SyncAV automatically adjusts atrioventricular delay (AVD) according to intrinsic AV intervals and may further improve synchrony. Their combination has not been assessed. The objective was to evaluate the improvement in electrical synchrony achieved by SyncAV combined with MPP in an international, multicenter study. METHODS: Patients with LBBB undergoing CRT implant with a quadripolar lead (Abbott Quartet™) were prospectively enrolled. QRS duration (QRSd) was measured by blinded observers from 12-lead ECG during: intrinsic conduction, BiV pacing (conventional biventricular pacing, nominal static AVD), MPP (2 LV cathodes maximally spaced, nominal static AVD), BiV + SyncAV, and MPP + SyncAV. All SyncAV offsets were individualized for each patient to yield the narrowest QRSd during BiV pacing. QRSd changes were compared by ANOVA and post hoc Tukey-Kramer tests. RESULTS: One hundred and three patients were enrolled (65.7 ± 12.1 years, 67% male, 37% ischemic, EF 26.4 ± 6.5%, PR 190.3 ± 39.1 ms). Relative to intrinsic conduction (QRSd of 165 ± 16 ms), BiV reduced QRSd by 11.9% to 145 ± 18 ms (P < 0.001 vs intrinsic), and MPP reduced QRSd by 13.3% to 142 ± 19 ms (P < 0.001 vs intrinsic). However, enabling SyncAV with a patient-optimized offset nearly doubled this QRSd reduction. BiV + SyncAV reduced QRSd by 22.0% to 128 ± 13 ms (P < 0.001 vs BiV), while MPP + SyncAV reduced QRSd further by 25.6% to 122 ± 14 ms (P < 0.05 vs BiV + SyncAV). CONCLUSION: SyncAV can significantly improve acute electrical synchrony beyond conventional CRT, with further improvement achieved by superimposing MPP.

Permanent pacing and conduction recovery in patients undergoing cardiac surgery for active infective endocarditis in an Australian Tertiary Center.

BACKGROUND: Postoperative heart block is common among patients undergoing surgery for infective endocarditis (IE). Limited data exists allowing cardiologists to predict who will require permanent pacemaker (PPM) implantation postoperatively. We aimed to determine the rate of postoperative PPM insertion, predictors for postoperative PPM, and describe PPM utilization and rates of device-related infection during follow-up. MATERIALS AND METHODS: A retrospective analysis was performed of 191 consecutive patients from a single institution who underwent cardiac surgery for IE between 2001 and 2017. Preoperative and operative predictors for postoperative PPM were evaluated using univariate and multivariate logistic regression. RESULTS: The rate of postoperative PPM implantation was 11% (17/154). The PPM group had more preoperative prolonged PR interval alone (33% vs 12%; P = .03), coexistent prolonged PR and QRS durations (13% vs 2%; P = .01), infection beyond the valve leaflets (82% vs 41%; P = .001), aortic root debridement (65% vs 23%; P = <.001), patch repair (47% vs 20%; P = .01), postoperative prolonged PR interval (50% vs 24%; P = .01), and prolonged QRS duration (47% vs 15%; P = .001). On multivariate analysis, infection beyond the valve leaflets emerged as an independent predictor for postoperative PPM (odds ratio, 1.94, 95% confidence interval, 1.14-3.28; P = .014). A reduction in PPM utilization was observed in five patients while eight patients continued to show significant ventricular pacing with no underlying rhythm at 12 months. There were no device-related infections. CONCLUSION: Postoperative PPM was required in 11% of patients undergoing surgery for IE over a 16-year period. Infection beyond the valve leaflet was an independent predictor for postoperative PPM insertion.

Electrical remodelling and response following cardiac resynchronization therapy: A novel analysis of intracardiac electrogram using a quadripolar lead.

BACKGROUND: Cardiac resynchronization therapy (CRT) improves morbidity and mortality in patients with heart failure. Although structural remodelling correlates with improved long-term outcomes, the role of electrical remodelling is poorly understood. This study aimed to evaluate electrical remodelling following CRT using a quadripolar left ventricular (LV) lead and to correlate this with structural remodelling. METHODS: Consecutive patients undergoing initial CRT implantation using a quadripolar LV lead were enrolled. Patients were followed up for 12 months. Twelve lead ECG, transthoracic echocardiogram, and evaluation of intracardiac electrograms (EGM) were performed. Measures included right and left ventricular lead intrinsic delay, RV-pacing to LV-sensing (RVp-LVs) delay, and LV-pacing to RV-sensing (LVp-RVs) delay. The electrical changes were then correlated with echocardiographic response to CRT, defined by ≥15% relative reduction in LVESV and ≥ 5% absolute improvement in EF on TTE. Activation sequence was determined using the quadripolar lead. RESULTS: Forty patients were enrolled. Mean intrinsic RV-LV EGM values decreased from 121.9 ± 14.7 ms to 109.1 ± 15.0 ms (P < .01), mean RVp-LVs EGM values from 146.7 ± 16.7 ms to 135.1 ± 13.1 ms, (P < .01), and mean LVp-RVs EGM values from 155.7 ± 18.1 ms to 144.2 ± 17.1 ms (P < .01). The improvement in intrinsic RV-LV EGM was 14.9 ± 8.5 ms in responders vs 8.9 ± 7.9 ms in nonresponders to CRT (P < .05). Changes in activation sequence did not correlate with CRT response. CONCLUSIONS: This novel study used EGMs from a quadripolar LV lead to demonstrate electrical remodelling occurs following CRT. A nonsignificant trend suggests that electrical remodelling in CRT is greater in responders compared to nonresponders, although further study is needed.

Right ventricular global longitudinal strain is an independent predictor of right ventricular function: a multimodality study of cardiac magnetic resonance imaging, real time three-dimensional echocardiography and speckle tracking echocardiography.

OBJECTIVES: Accurate assessment of right ventricular (RV) systolic function is important, as it is an established predictor of mortality in cardiac and respiratory diseases. We aimed to compare speckle tracking-derived longitudinal deformation measurements with traditional two-dimensional (2D) echocardiographic parameters, as well as real time three-dimensional echocardiography (RT3DE) and cardiac magnetic resonance imaging (CMR)-derived RV volumes and ejection fraction (EF). METHOD: Subjects referred for CMR also underwent echocardiography. On both RT3DE and CMR, we measured RV volumes and EF. On 2D echocardiography, we analyzed RV fractional area change, RV internal diastolic diameter, tricuspid annular plane systolic excursion, tricuspid annular tissue Doppler-derived velocity, myocardial performance index, and RV global longitudinal strain (RV GLS). RESULTS: Sixty subjects were recruited (mean age = 45 ± 10 years; 60% male). RV GLS (R = -0.69, P < 0.001) and RT3DE RVEF (R = 0.56, P < 0.001) correlated well with CMR RVEF. RT3DE RV end-diastolic (RVEDV) and end-systolic (RVESV) volumes also correlated with CMR RV volumes: RVEDV, R = 0.74, P < 0.001 and RVESV, R = 0.84, P < 0.001. In addition, RV GLS best predicted the presence of RV dysfunction, defined as RVEF <48% on CMR (hazard ratio = 7.0 [1.5-31.7], P < 0.01). On receiver operator characteristic analysis, a RV GLS of -20% was the most sensitive and specific predictor of RV dysfunction (AUC 0.8 [0.57-1.0], P < 0.02). CONCLUSION: RVEF and volumes estimated on RT3DE were closely correlated with CMR measurements. When compared to more traditional markers of RV systolic function and RT3DE, RVGLS produced the highest correlation with CMR RVEF and was a good predictor of RV dysfunction. RV GLS should be considered a complementary modality to RT3DE and CMR in the assessment of RV systolic function.

Prevalence, predictors and evolution of echocardiographically defined cardiac abnormalities in adults with type 1 diabetes: an observational cohort study.

AIMS/HYPOTHESIS: The aims of this observational study were to determine the prevalence and predictors of an abnormal echocardiogram in adults with type 1 diabetes, and to assess the evolution of changes in a subset of subjects. METHODS: Cardiac function and structure were prospectively investigated by comprehensive transthoracic echocardiographic techniques in asymptomatic adults with type 1 diabetes seen in the ambulatory care setting. RESULTS: We recruited 136 subjects (mean age 39 years, SD 14 years) with a median diabetes duration of 21 years [25(th), 75(th) interquartile range; 11, 29]. An abnormal echocardiogram was present in 29% of subjects; diastolic dysfunction in 69%, left ventricular hypertrophy in 38% and systolic dysfunction in 10%. The independent predictors of an abnormal echocardiogram were age, with a 9-fold increase in those ≥40 years (OR 9.40 [95% CI 2.68-33.04], P <0.0001), and increased body mass index (BMI), with a 17% increase in risk (P=0.04). A second echocardiogram was available in 65 subjects (3.8±1.7 years later). The results showed that one in five with a normal first study had developed an abnormal second study, mainly diastolic dysfunction, with age being the only independent predictor of progression (P=0.006). CONCLUSIONS/INTERPRETATION: Subclinical echocardiographic abnormalities are common in asymptomatic type 1 diabetes adults, and changes are progressive. The addition of an echocardiogram to complication surveillance programs in those with type 1 diabetes aged ≥40 years may represent a cost-effective way to screen for, and aggressively treat, occult cardiac disease.

Cardiorenal anemia syndrome as a prognosticator for death in heart failure.

Anemia and chronic kidney disease are common in patients with heart failure (HF) and are associated with adverse outcomes. We analyzed the effect of cardiorenal anemia (CRA) syndrome, defined as anemia (hemoglobin <130 g/L for men, <120 g/L for women) and stage 3 or greater chronic kidney disease (estimated glomerular filtration rate <60 ml/min/1.73 m(2)), in outpatients with HF. Consecutive patients with HF were prospectively enrolled from 2000 to 2005 (n = 748). The baseline clinical characteristics, pathology test results, and medication use were compared between those with and without CRA syndrome. The primary end point was all-cause mortality. The mean follow-up was 2.5 ± 1.6 years, with a left ventricular ejection fraction <45% present in 70% of patients. Angiotensin-converting enzyme inhibitors, ß blockers, and spironolactone were used in 87%, 67%, and 37%, respectively. CRA syndrome was present in 224 patients (30%). These patients had greater all-cause mortality (51% vs 26%, p <0.001), older age (mean 77 ± 8 vs 67 ± 14 years, p <0.001), and greater rates of diabetes mellitus (35% vs 23%, p <0.001) and ischemic heart disease (50% vs 35%, p <0.001). The independent predictors of mortality were CRA syndrome (hazard ratio 2.0, 95% confidence interval 1.4 to 2.8, p <0.001), left ventricular systolic dysfunction per grade (hazard ratio 1.5, 95% confidence interval 1.3 to 1.8, p <0.001), the absence of a ß blocker (hazard ratio 1.6, 95% confidence interval 1.1 to 2.2, p = 0.005), New York Heart Association class per class (hazard ratio 1.5, 95% confidence interval 1.2 to 1.9, p <0.01), and age per decade (hazard ratio 1.6, 95% confidence interval 1.4 to 2.0, p <0.001). In conclusion, CRA syndrome was common in patients with HF and was an independent predictor of all-cause mortality. Consideration should be given to identifying CRA syndrome and modifying reversible factors.

Usefulness of the Charlson co-morbidity index to predict outcomes in patients >60 years old with aortic stenosis during 18 years of follow-up.

The present study assessed the effect of age and co-morbidity on the outcomes of mild, moderate, and severe aortic stenosis (AS) in patients aged >60 years during 18 years of follow-up. The outcomes evaluated were hemodynamic progression, a composite cardiac mortality or aortic valve replacement (AVR) end point, and all-cause mortality. Consecutive Department of Veterans Affairs patients (aged >60 years) with AS were prospectively enrolled from 1988 to 1994 and followed until 2008 (n = 239). The baseline demographic, co-morbidity, and echocardiographic parameters were recorded. At enrollment, the mean age was 74 ± 6 years, and 78% were men. The annualized mean aortic valve gradient progression was 4 ± 4, 6 ± 5, and 10 ± 8 mm Hg for mild, moderate, and severe AS, respectively (p <0.001). During a mean follow-up of 8 ± 5 years, 206 deaths (52% cardiac) and 91 AVRs were recorded. The AVR/cardiac mortality event rate at 1, 5, and 10 years was 2%, 26%, and 50% for mild AS, 13%, 63%, and 69% for moderate AS, and 66%, 95%, and 95% for severe AS (p <0.001). During the study period, 132 patients developed severe AS. The survival rate at 1, 5, and 10 years was 60 ± 7%, 14 ± 5%, and 5 ± 3% with conservative management and 98 ± 2%, 82 ± 4%, and 50 ± 5% after AVR, respectively (p <0.001). The independent predictors of all-cause mortality were the age-adjusted Charlson co-morbidity index (hazard ratio 1.24, p <0.001), AVR (hazard ratio 0.40, p <0.001), and grade of left ventricular dysfunction (hazard ratio 1.36, p = 0.01). In conclusion, the prognostic significance of AS is determined by the hemodynamic severity, left ventricular function, and the presence of symptoms, in the context of age and co-morbidities. The age-adjusted Charlson co-morbidity index provides crucial prognostic information to guide the surgical risk/benefit discussions for patients with severe AS.

The CTGF gene -945 G/C polymorphism is not associated with cardiac or kidney complications in subjects with type 2 diabetes.

BACKGROUND: Connective tissue growth factor (CTGF) has been implicated in the cardiac and kidney complications of type 2 diabetes, and the CTGF -945 G/C polymorphism is associated with susceptibility to systemic sclerosis, a disease characterised by tissue fibrosis. This study investigated the association of the CTGF -945 G/C promoter variant with cardiac complications (left ventricular (LV) hypertrophy (LVH), diastolic and systolic dysfunction) and chronic kidney disease (CKD) in type 2 diabetes. METHODS: The CTGF -945 G/C polymorphism (rs6918698) was examined in 495 Caucasian subjects with type 2 diabetes. Cardiac structure and function were assessed by transthoracic echocardiography. Kidney function was assessed using estimated glomerular filtration rate (eGFR) and albuminuria, and CKD defined as the presence of kidney damage (decreased kidney function (eGFR <60 ml/min/1.73 m2) or albuminuria). RESULTS: The mean age ± SD of the cohort was 62 ± 14 years, with a body mass index (BMI) of 31 ± 6 kg/m2 and median diabetes duration of 11 years [25th, 75th interquartile range; 5, 18]. An abnormal echocardiogram was present in 73% of subjects; of these, 8% had LVH alone, 74% had diastolic dysfunction and 18% had systolic ± diastolic dysfunction. CKD was present in 42% of subjects. There were no significant associations between the CTGF -945 G/C polymorphism and echocardiographic parameters of LV mass or cardiac function, or kidney function both before and after adjustment for covariates of age, gender, BMI, blood pressure and hypertension. CTGF -945 genotypes were not associated with the cardiac complications of LVH, diastolic or systolic dysfunction, nor with CKD. CONCLUSIONS: In Caucasians with type 2 diabetes, genetic variation in the CTGF -945 G/C polymorphism is not associated with cardiac or kidney complications.

Beta blocker use in subjects with type 2 diabetes mellitus and systolic heart failure does not worsen glycaemic control.

BACKGROUND: The prognostic benefits of beta-blockers (BB) in patients with systolic heart failure (SHF) are known but despite this, in patients with diabetes they are underutilized. The aim of this study was to assess the effect of beta-blockers (BB) on glycaemic control in patients with Type 2 Diabetes (T2DM) and systolic heart failure (SHF) stratified to beta-1 selective (Bisoprolol) vs. nonselective BB (Carvedilol). METHODS: This observational, cohort study was conducted in patients with T2DM and SHF attending an Australian tertiary teaching hospital's heart failure services. The primary endpoint was glycaemic control measured by glycosylated haemoglobin (HbA1c) at initiation and top dose of BB. Secondary endpoints included microalbuminuria, changes in lipid profile and estimated glomerular filtration rate (eGFR). RESULTS: 125 patients were assessed. Both groups were well matched for gender, NYHA class and use of guideline validated heart failure and diabetic medications. The mean treatment duration was 1.9 ± 1.1 years with carvedilol and 1.4 ± 1.0 years with bisoprolol (p = ns). The carvedilol group achieved a reduction in HbA1c (7.8 ± 0.21% to 7.3 ± 0.17%, p = 0.02) whereas the bisoprolol group showed no change in HbA1c (7.0 ± 0.20% to 6.9 ± 0.23%, p = 0.92). There was no significant difference in the change in HbA1c from baseline to peak BB dose in the carvedilol group compared to the bisoprolol group. There was a similar deterioration in eGFR, but no significant changes in lipid profile or microalbuminuria in both groups (p = ns). CONCLUSION: BB use did not worsen glycaemic control, lipid profile or albuminuria status in subjects with SHF and T2DM. Carvedilol significantly improved glycemic control in subjects with SHF and T2DM and this improvement was non significantly better than that obtained with bisoprolol. BB's should not be withheld from patients with T2DM and SHF.

Association of ACE2 genetic variants with blood pressure, left ventricular mass, and cardiac function in Caucasians with type 2 diabetes.

BACKGROUND: Cardiovascular disease is common in diabetes, and is associated with activation of the renin-angiotensin system (RAS). Angiotensin-converting enzyme (ACE)2 is a recently described member of the RAS, and this study investigated whether ACE2 polymorphisms are associated with hypertension, left ventricular (LV) mass, and cardiac function in type 2 diabetes. METHODS: Variants in ACE2 (rs1978124, rs2074192, rs4240157, rs4646156, rs4646188) were examined in 503 Caucasian subjects with type 2 diabetes. As ACE2 is located on the X chromosome, analyses were performed separately for men and women. Hypertension was defined by a history of hypertension, and/or antihypertensive medications or blood pressure (BP) >130/80 mm Hg. LV mass and systolic function (ejection fraction) were assessed by transthoracic echocardiography. RESULTS: In men, hypertension was more prevalent with the ACE2 rs2074192 C allele (P = 0.023), rs4240157 G allele (P = 0.016) and rs4646188 T allele (P = 0.006). In men, the rs1978124 A allele was associated with a significantly lower ejection fraction compared to the G allele (62.3 ± 13.3 vs. 67.2 ± 10.9%, P = 0.002). This association remained significant after covariate adjustment for age, body mass index, hypertension, antihypertensive treatment, and BP. In women, the prevalence of hypertension was higher (P = 0.009) with the rs4240157 G allele, and the rs1978124 A allele was associated with significantly higher LV mass (P = 0.008). CONCLUSIONS: In Caucasians with type 2 diabetes, genetic variation in ACE2 is associated with hypertension and reduced systolic function in men, and hypertension and increased LV mass in women.

Validation of rapid automated tissue synchronization imaging for the assessment of cardiac dyssynchrony in sinus and non-sinus rhythm.

AIMS: Cardiac resynchronization therapy is showing benefits for an increasing number of indications but fails to predict response in up to 20-30% of subjects. Echocardiographically assessed dyssynchrony has been proposed as a potential stratifier but current methods are time-consuming and suffer poor reproducibility, thus limiting their clinical utility. This study compared the accuracy, time efficiency, and reproducibility of automated tissue synchronization imaging (Auto TSI) vs. established manual tissue velocity imaging (TVI) techniques for the assessment of intra-ventricular dyssynchrony in sinus and non-sinus rhythm. METHODS AND RESULTS: Fifty consecutive stable systolic heart failure patients on optimal guideline-based medical therapy underwent intra-ventricular dyssynchrony assessment [time to peak velocity (Ts), septal to lateral delay (SLD), and dyssynchrony index (DI)] with TVI and Auto TSI techniques, enabling the assessment of agreement, time efficiency, and reproducibility. Statistical analyses included Pearson's correlation, Bland-Altman's statistics, and coefficient of reproducibility. There was excellent agreement between Auto TSI and TVI for the measurement of Ts [r=0.92, P<0.001, limits of agreement (LOA): -27.3 to 56.5 ms], SLD (r=0.94, P<0.001, LOA: -41 to 49 ms), and DI (r=0.89, P<0.001, LOA: -12.2 to 12.6 ms) which persisted irrespective of cardiac rhythm [Ts: sinus (n=32) r=0.93, P<0.001; non-sinus (n=18) r=0.91, P<0.001]. Automated TSI was more time efficient (3±1 vs. 14±2 min, P<0.001) and demonstrated superior reproducibility: intra-observer (5.5 vs. 9.6%) and inter-observer variability (9.5 vs. 13.4%). CONCLUSION: Automated TSI enables rapid, reproducible intra-ventricular dyssynchrony assessment and overcomes some of the limitations of conventional techniques in sinus and non-sinus rhythm.