Keiko Ryo

Usefulness of Echocardiographically Guided Left Ventricular Lead Placement for Cardiac Resynchronization Therapy in Patients With Intermediate QRS Width and Non–Left Bundle Branch Block Morphology

The current guidelines most strongly support cardiac resynchronization therapy (CRT) for patients with heart failure with a QRS width of ≥150 ms and left bundle branch block (LBBB). Our objective was to assess the potential benefit of echocardiographically guided left ventricular (LV) lead positioning for patients with a QRS width <150 ms or non-LBBB as a substudy of the Speckle Tracking Assisted Resynchronization Therapy for Electrode Region (STARTER) prospective, randomized controlled trial. The STARTER trial randomized 187 patients with heart failure, a QRS of ≥120 ms, and ejection fraction of ≤35% to LV lead guided to the site of latest mechanical activation by speckle tracking radial strain versus routine implantation. The predefined primary end point was heart failure hospitalization or death within 2 years. This substudy included 151 CRT patients with matching echocardiographic and LV lead position data and complete follow-up data. Patients with a QRS width of 120 to 149 ms or non-LBBB and LV lead concordant or adjacent to the site of latest mechanical activation had favorable outcomes after CRT similar to those with LBBB or a QRS width of ≥150 ms. In contrast, patients with a QRS of 120 to 149 ms or non-LBBB and remote LV leads had unfavorable outcomes (hazard ratio 5.45, 95% confidence interval 2.36 to 12.6, p <0.001, and hazard ratio 4.92, 95% confidence interval 2.12 to 11.39, p <0.001, respectively, with significant interaction after adjusting for baseline variables, p = 0.038 and p = 0.008). In conclusion, LV lead positioning with respect to the echocardiographic site of latest activation was significantly associated with more favorable clinical outcomes in patients with a QRS duration <150 ms and/or non-LBBB. Additional prospective study is warranted.

Right ventricular apical pacing-induced left ventricular dyssynchrony is associated with a subsequent decline in ejection fraction.

BACKGROUND In patients with normal left ventricular (LV) ejection fraction (EF), the interposition of chronic, high-dose right ventricular apical (RVA) pacing may produce late EF decline. OBJECTIVE To test the hypothesis that LV dyssynchrony, defined echocardiographically and apparent early after interposition of pacing, would be greater in patients who subsequently demonstrated EF decline. METHODS Ninety-one patients with normal prepacing EF who underwent atrioventricular node ablation and subsequent high-dose RVA pacing were studied. Transthoracic echocardiograms were performed early (median 4 months) and late (median 28 months) after interposition of pacing, with a significant decline in EF between these studies defined as ≥5%. Speckle-tracking longitudinal strain analysis of the early echocardiogram was performed to quantify dyssynchrony. In addition to standard dyssynchrony indices, a novel index of apex-to-base mechanical propagation delay (MPD) was used. RESULTS Multivariable analysis determined that MPD of the septum correlated with a significant decline in EF, independent of all other dyssynchrony, clinical, or pacing variables. A septal MPD value exceeding 50 ms was associated with EF decline at 81% sensitivity and 88% specificity. CONCLUSIONS Dyssynchrony, in particular septal MPD, measured early after interposition of high-dose RVA pacing predicted a significant late decline in EF in patients who had normal prepacing EF.

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.

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.

BIVENTRICULAR REMODELING BY THREE DIMENSIONAL ECHOCARDIOGRAPHY IS ASSOCIATED WITH OUTCOME IN PATIENTS WITH PULMONARY HYPERTENSION

Right ventricular (RV) remodeling is an important factor associated with outcome in patients with pulmonary hypertension (PH). However, the influence of RV remodeling on left ventricular (LV) morphology in PH and its association with outcomes are unclear. We studied 83 PH patients with 3-

INTERVENTRICULAR MECHANICAL DELAY: A SIMPLE, REPRODUCIBLE INDEX PREDICTIVE OF LONG TERM OUTCOME AFTER CARDIAC RESYNCHRONIZATION THERAPY IN PATIENTS WITH INTERMEDIATE QRS WIDTH AND NON-LEFT BUNDLE BRANCH BLOCK MORPHOLOGY

Echo dyssynchrony has been criticized because of variability in cardiac resynchronization therapy (CRT) and guidelines focus on QRS width and morphology. Our aim was to determine the prognostic utility of interventricular mechanical delay (IVMD) as a simple, highly reproducible dyssynchrony index