Antonia Delgado-Montero

Differentiating Electromechanical From Non-Electrical Substrates of Mechanical Discoordination to Identify Responders to Cardiac Resynchronization Therapy.

Background—Left ventricular (LV) mechanical discoordination, often referred to as dyssynchrony, is often observed in patients with heart failure regardless of QRS duration. We hypothesized that different myocardial substrates for LV mechanical discoordination exist from (1) electromechanical activation delay, (2) regional differences in contractility, or (3) regional scar and that we could differentiate electromechanical substrates responsive to cardiac resynchronization therapy (CRT) from unresponsive non–electrical substrates. Methods and Results—First, we used computer simulations to characterize mechanical discoordination patterns arising from electromechanical and non–electrical substrates and accordingly devise the novel systolic stretch index (SSI), as the sum of posterolateral systolic prestretch and septal systolic rebound stretch. Second, 191 patients with heart failure (QRS duration ≥120 ms; LV ejection fraction ⩽35%) had baseline SSI quantified by automated echocardiographic radial strain analysis. Patients with SSI≥9.7% had significantly less heart failure hospitalizations or deaths 2 years after CRT (hazard ratio, 0.32; 95% confidence interval, 0.19–0.53; P<0.001) and less deaths, transplants, or LV assist devices (hazard ratio, 0.28; 95% confidence interval, 0.15–0.55; P<0.001). Furthermore, in a subgroup of 113 patients with intermediate electrocardiographic criteria (QRS duration of 120–149 ms or non–left bundle branch block), SSI≥9.7% was independently associated with significantly less heart failure hospitalizations or deaths (hazard ratio, 0.41; 95% confidence interval, 0.23–0.79; P=0.004) and less deaths, transplants, or LV assist devices (hazard ratio, 0.27; 95% confidence interval, 0.12–0.60; P=0.001). Conclusions—Computer simulations differentiated patterns of LV mechanical discoordination caused by electromechanical substrates responsive to CRT from those related to regional hypocontractility or scar unresponsive to CRT. The novel SSI identified patients who benefited more favorably from CRT, including those with intermediate electrocardiographic criteria, where CRT response is less certain by ECG alone.

Characterization of Right Ventricular Remodeling in Pulmonary Hypertension Associated With Patient Outcomes by 3-Dimensional Wall Motion Tracking Echocardiography

Background—Adverse right ventricular (RV) remodeling has significant prognostic and therapeutic implications to patients with pulmonary hypertension (PH). However, differentiating RV adaption from adverse remodeling associated with poor outcomes is difficult. We hypothesized that novel 3-dimensional (3D) wall motion tracking echocardiography can differentiate morphological features of RV adaption from adverse remodeling heralding an unfavorable short-term prognosis in patients with PH. Methods and Results—We studied 112 subjects: 92 patients with PH and 20 normal controls with 3D wall motion tracking for RV end-systolic volume index (ESVi), RV ejection fraction (EF), and RV global area strain. Patients with PH also had invasive hemodynamic measurements. Pressure–volume relations classified patients with PH into 3 groups, such as RV adapted, RV adapted–remodeled, and RV adverse–remodeled. The predefined combined end point was PH-related hospitalization, death, or lung surgery (lung transplantation or pulmonary endarterectomy) during 6 months. The 92 patients with PH had significantly larger RV volumes, lower RVEF and global area strain than normal controls as expected. Patients with PH classified as RV adapted (ESVi, ⩽72 mL/m2) had a more favorable clinical outcome than those classified as RV adapted–remodeled (ESVi, 73–113 mL/m2) or RV adverse–remodeled (ESVi, ≥114 mL/m2): hazard ratio, 0.15; 95% confidence intervals, 0.07 to 0.39; P<0.0001. RV adverse–remodeled patients (ESVi, ≥114 mL/m2) had worse short-term outcome than the RV adapted–remodeled patients: hazard ratio, 2.2; 95% confidence interval, 0.91 to 5.39; P=0.04. Conclusions—Quantitative 3D echocardiography in patients with PH demonstrated morphological subsets of RV adaption and remodeling associated with clinical outcomes.

Right Ventricular Function in Peripartum Cardiomyopathy at Presentation Is Associated With Subsequent Left Ventricular Recovery and Clinical Outcomes

Background—Peripartum cardiomyopathy has variable disease progression and left ventricular (LV) recovery. We hypothesized that baseline right ventricular (RV) size and function are associated with LV recovery and outcome. Methods and Results—Investigations of Pregnancy-Associated Cardiomyopathy was a prospective 30-center study of 100 peripartum cardiomyopathy women with LV ejection fraction (LVEF) <45% within 13 weeks after delivery. Baseline RV function was assessed by echocardiographic end-diastolic area, end-systolic area, fractional area change, tricuspid annular plane excursion, and RV speckle-tracking longitudinal strain. LV recovery was defined as LVEF of ≥50% at 1 year, persistent severe LV dysfunction as LVEF of ⩽35%, and major events as death, transplant, or LV assist device implantation. RV measurements were feasible for 90 of the 96 patients (94%) with echocardiograms available. Mean baseline LVEF was 36±9%. RV fractional area change was <35% in 38% of patients. Of 84 patients with 1-year follow-up data, 63 (75%) had LV recovery and 11 (13%) had LVEF of ⩽35% or a major event (4 LV assist devices and 2 deaths). Tricuspid annular plane excursion and RV strain did not predict outcome. Baseline RV fractional area change by multivariable analysis was independently associated with subsequent LV recovery and clinical outcome. Conclusions—Peripartum cardiomyopathy patients had a high incidence of LV recovery, but a significant minority had persistent LV dysfunction or a major clinical event by 1 year. RV function per echocardiographic fractional area change at presentation was associated with subsequent LV recovery and clinical outcomes and thus is prognostically important.

Additive Prognostic Value of Echocardiographic Global Longitudinal and Global Circumferential Strain to Electrocardiographic Criteria in Patients With Heart Failure Undergoing Cardiac Resynchronization Therapy

Background—Response to cardiac resynchronization therapy is most favorable in patients with heart failure with QRS duration ≥150 ms and left bundle branch block and less predictable in those with QRS width 120 to 149 ms or non–left bundle branch block. Methods and Results—We studied 205 patients with heart failure referred for cardiac resynchronization therapy with QRS ≥120 ms and ejection fraction ⩽35%. We tested the hypothesis that contractile function using speckle-tracking echocardiographic global circumferential strain (GCS) from 2 short-axis views and global longitudinal strain (GLS) from 3 apical views add prognostic value to electrocardiographic criteria. There were 112 patients (55%) with GLS >−9% and 136 patients (66%) with GCS >−9%. During 4 years, 81 patients reached the combined primary end point (death, circulatory support, or transplant) and 120 reached the secondary end point (heart failure hospitalization or death). Both GLS >−9% and GCS >−9% were associated with increased risk of unfavorable events as follows: for the primary end point (hazard ratio=2.91; 95% confidence interval, 1.88–4.49; P<0.001) and (hazard ratio=3.73; 95% confidence interval, 2.39–5.82; P<0.001) for the secondary end point (hazard ratio=2.10; 95% confidence interval, 1.45–3.05; P<0.001) and (hazard ratio=3.25; 95% confidence interval, 2.23–4.75; P<0.001). In a prespecified subgroup of 120 patients with QRS 120 to 149 ms or non–left bundle branch block, significant associations of baseline GLS and GCS and outcomes remained: P=0.014 and P=0.002 for the primary end point and P=0.049 and P=0.001 for the secondary end point. Global strain measures had additive prognostic value to routine clinical or electrocardiographic parameters (P<0.001). Conclusions—Baseline GCS and GLS were significantly associated with long-term outcome after cardiac resynchronization therapy and had additive prognostic value to routine clinical and electrocardiographic selection criteria for cardiac resynchronization therapy.

Comparative long-term outcomes after cardiac resynchronization therapy in right ventricular paced patients versus native wide left bundle branch block patients

BACKGROUND The current guidelines do not clearly state when we should upgrade a patient with right ventricular pacing (RVP) to cardiac resynchronization therapy (CRT), although the deleterious effect of chronic RVP has been established with recent trials. OBJECTIVES The aims of this study were to compare the long-term survival after CRT in patients upgraded from RVP with that in patients with left bundle branch block (LBBB) with QRS duration ≥ 150 ms and to compare the mechanical properties associated with CRT response in these groups. METHODS Overall, 135 patients with implanted CRT from a single center (85 (63%) with native wide LBBB and 50 (37%) with RVP) were studied prospectively. Baseline left ventricular typical contraction pattern was determined using speckle tracking echocardiography in the apical 4-chamber view. The predefined end point was death, heart transplantation, or left ventricular assist device implantation over a period of 4 years. RESULTS Patients with RVP had a significantly favorable long-term outcomes with adjusted hazard ratio of 0.36 (95% confidence interval 0.14-0.96; P = .04). Both groups had ~70% of patients with typical contraction pattern. The absence of typical contraction pattern was associated with a higher risk of an end point with adjusted hazard ratio of 5.43 (95% confidence interval 2.31-12.72; P < .001). In patients with typical contraction pattern, activation of the apical septal segment occurred more frequently in the RVP group and of the base or mid septal segments in the LBBB group. CONCLUSION Patients with HF upgraded from RVP have more favorable long-term outcomes after CRT than do native LBBB patients with QRS duration ≥ 150 ms. Contraction pattern assessment can be used to identify potential responders in the RVP group.

Mechanical Dyssynchrony by Tissue Doppler Cross-Correlation is Associated with Risk for Complex Ventricular Arrhythmias after Cardiac Resynchronization Therapy.

BACKGROUND Tissue Doppler cross-correlation analysis has been shown to be associated with long-term survival after cardiac resynchronization defibrillator therapy (CRT-D). Its association with ventricular arrhythmia (VA) is unknown. METHODS From two centers 151 CRT-D patients (New York Heart Association functional classes II-IV, ejection fraction ≤ 35%, and QRS duration ≥ 120 msec) were prospectively included. Tissue Doppler cross-correlation analysis of myocardial acceleration curves from the basal segments in the apical views both at baseline and 6 months after CRT-D implantation was performed. Patients were divided into four subgroups on the basis of dyssynchrony at baseline and follow-up after CRT-D. Outcome events were predefined as appropriate antitachycardia pacing, shock, or death over 2 years. RESULTS Mechanical dyssynchrony was present in 97 patients (64%) at baseline. At follow-up, 42 of these 97 patients (43%) had persistent dyssynchrony. Furthermore, among 54 patients with no dyssynchrony at baseline, 15 (28%) had onset of new dyssynchrony after CRT-D. In comparison with the group with reduced dyssynchrony, patients with persistent dyssynchrony after CRT-D were associated with a substantially increased risk for VA (hazard ratio [HR], 4.4; 95% CI, 1.2-16.3; P = .03) and VA or death (HR, 4.0; 95% CI, 1.7-9.6; P = .002) after adjusting for other covariates. Similarly, patients with new dyssynchrony had increased risk for VA (HR, 10.6; 95% CI, 2.8-40.4; P = .001) and VA or death (HR, 5.0; 95% CI, 1.8-13.5; P = .002). CONCLUSIONS Persistent and new mechanical dyssynchrony after CRT-D was associated with subsequent complex VA. Dyssynchrony after CRT-D is a marker of poor prognosis.

Interaction of Left Ventricular Remodeling and Regional Dyssynchrony on Long-Term Prognosis after Cardiac Resynchronization Therapy

Background: Left ventricular (LV) remodeling in heart failure (HF) manifested by chamber dilatation is associated with worse clinical outcomes. However, the impact of LV dilatation on the association of measures of dyssynchrony with long‐term prognosis and resynchronization potential after cardiac resynchronization therapy (CRT) remains unclear. Methods: Two hundred sixty CRT patients in New York Heart Association classes II to IV, with ejection fractions ≤ 35% and QRS intervals ≥ 120 msec, were prospectively studied. Quantitative echocardiographic assessment of LV volumes and mechanical dyssynchrony by radial strain was conducted at both baseline and 6‐month follow‐up. Primary outcome events were predefined as death or HF hospitalization, and secondary outcome events were defined as all‐cause death over the 4 years after CRT. Results: Patients were divided into two groups using the median of the baseline indexed LV end‐diastolic volume (EDVI). Patients with less dilated left ventricles (EDVI < 90 mL/m2) had improved prognosis compared to those with severely dilated left ventricles (EDVI ≥ 90 mL/m2) for both primary (adjusted hazard ratio [HR], 2.20; 95% CI, 1.44–3.38; P < .01) and secondary (adjusted HR, 1.94; 95% CI, 1.21–3.11; P < .01) events. Similarly, reduction in baseline dyssynchrony was associated with good prognosis for both the primary (HR, 0.39; 95% CI, 0.23–0.68; P = .001) and secondary (HR, 0.41; 95% CI, 0.22–0.75; P = .004) events. A linear association was found between each 10% reduction in dyssynchrony and events (P < .01). Notably, patients with less dilated left ventricles had nearly fourfold more frequent improvement in dyssynchrony compared to those with severely dilated left ventricles (odds ratio, 4.10; 95% CI, 1.81–9.28; P < .01). No other baseline prognostic marker was associated with the resynchronization ability of CRT. Conclusions: Patients with severe LV remodeling (EDVI ≥ 90 mL/m2) have a poor prognosis following CRT device implantation. This is most likely due to impaired resynchronization efficacy. HighlightsReduction in baseline mechanical dyssynchrony after CRT in patients with HF is associated with significant reduction in mortality and HF hospitalization.Patients with extensive remodeling has poor prognosis after CRT because of a lack of mechanical resynchronization after CRT.There is a linear association between the amount of reduction in mechanical dyssynchrony after CRT device implantation and survival. Devising a strategy to follow patients treated with CRT devices by the assessment of dyssynchrony could be beneficial.

Stasis Mapping Using Ultrasound: A Prospective Study in Acute Myocardial Infarction

During the subacute phase of acute myocardial infarction (AMI), the incidence of left ventricular thrombosis (LVT) can be as high as 15% to 20%. A method for assessing the risk of LVT would be of particular value in the setting of AMI, because prophylactic anticoagulation must be balanced against

CORRELATION OF A NEW ECHOCARDIOGRAPHIC INDEX OF RIGHT VENTRICULAR REMODELING IN PULMONARY HYPERTENSION WITH INVASIVE HEMODYNAMICS IN RAT MODEL

Right ventricular (RV) remodeling is important to humans with pulmonary hypertension (PH). Small animal models of PH are used to investigate novel therapies, but assessment of RV remodeling is difficult. The aim was to compare a new RV remodeling index (echo RV to LV area ratio) to invasive

PACEMAKER DEPENDENCY AFTER TRANSCATHETER AORTIC VALVE REPLACEMENT IS ASSOCIATED WITH REDUCTION IN GLOBAL LEFT VENTRICULAR FUNCTION

Consequences of conduction abnormalities requiring a permanent pacemaker (PPM) after transcatheter aortic valve replacement (TAVR) are still unclear. Our aim was to determine risk factors for PPM after TAVR and associated effects on LV function over time. Of 389 consecutive TAVR patients, we