Flow-status and survival in severe aortic stenosis treated with TAVI – is flow rate superior to stroke volume index?

Background

Low-flow status, currently defined as a stroke volume index (SVi) <35 mL/m2, is an important prognostic predictor for mortality after Transcatheter Aortic Valve Implantation (TAVI) for severe aortic stenosis (SAS). However, transaortic flow rate (FR) – defined as stroke volume divided by left ventricle ejection time - has recently been suggested to be superior to SVi in defining low-flow states, as it reflects more closely valvular resistance, while being independent of body surface area. Low FR is most consistently defined as FR<200 mL/s.

Purpose

Determine the prognostic impact of FR and SVi before TAVI in survival after intervention for SAS.

Methods

A single-centre retrospective database of all TAVI performed between 2011 and 2019 was analyzed, and cases with pre-intervention echocardiograms available were included. Low-flow patients were identified according to basal FR (<200 mL/s) or SVi (<35 mL/m2), and compared with normal-flow cases. The primary endpoint was defined as time to all-cause death or last follow-up. The impact of flow-status (using FR or SVi) in survival was assessed using Kaplan-Meier curves and log-rank test, as well as Cox proportional hazard model adjusted for EuroSCORE II, using FR or SVi either as categorical or continuous variables. A subanalysis further compared patients with preserved and reduced ejection fraction (EF, <52%). p<0.05 was considered statistically significant.

Results

From 657 TAVI performed, 490 (74.6%) cases were included, with a median follow-up of 43 months. From those, 59.6% were defined as low-flow according to FR, and 43.3% using SVi. Low-flow patients, using each parameter, were of higher surgical risk (EuroSCORE II and STS scores), had more advanced NYHA classes, worse estimated creatinine clearance, and suffered more frequently from coronary artery disease. Low-FR patients were also older, and more predominantly female. Atrial fibrillation was more prevalent among low SVi cases. Functional aortic valve area was lower in low-flow patients using both assessments, but low-SVi was also associated with lower transaortic gradients, as well as lower EF before and after TAVI. Regarding all-cause mortality, low-SVi was associated with worse survival [p=0.02, hazard ratio (HR) 1.43 (1.05–1.94)], but not low-FR (p=0.4). However, low-SVi, when adjusted for EuroScore II, was no longer a predictor of all-cause mortality (p=0.08). When considering FR and SVi as continuous variables, a higher SVi (but not FR) was associated with better survival (HR 0.98, p=0.047) in multivariable analysis adjusted for EuroSCORE II. When stratifying according to preserved and reduced EF, both FR and SVi did not predict all-cause mortality.

Conclusions

Low-flow states are common in SAS population treated with TAVI, being frequently associated with worse symptoms and higher procedural risk. Low-SVi, but not low-FR, negatively impacts survival after intervention, representing a marker for prognosis after TAVI.

Funding Acknowledgement

Type of funding sources: None.

Acute total occlusion of the unprotected left main coronary artery – patient characteristics and outcomes

Background

Acute total occlusion of the unprotected left main coronary artery (ATOLMCA) is a dramatic entity with very high mortality. Owing to its infrequency, there is limited and inconsistent data regarding this population.

Purpose

To describe the clinical presentation, short- and long-term outcomes of patients with ATOLMCA.

Methods

This retrospective multicentric cohort study included all patients presenting with acute (<12h) myocardial infarction (MI) due to ATOLMCA (Thrombolysis In Myocardial Infarction - TIMI=0) between January 2008 and December 2020 in three tertiary hospitals.

Results

In the period of the study, 11,036 emergent coronary angiographies were performed in the participating centers, 59 of which were ATOLMCA (0.5%). Mean age of patients at the time of the event was 61.2 (±12.2) years. Seventy-three percent were male. At presentation, 72.9% of patients were in cardiogenic shock, and aborted cardiac arrest occurred in 27.1%. Right dominance was present in all patients except one, who had a balanced dominance. Primary percutaneous coronary intervention (PCI) was performed in 89.8% of the patients, with angiographic success being achieved in 55.6% of the procedures. Overall, the in-hospital mortality rate was 57.6%. Mortality was significantly higher in patients without angiographic criteria for PCI success (87.5 vs 36.7%, p<0.001). Among survivors, 91.7% were still alive at 1-year and 66.7% at 5 years of follow-up.

Conclusion

Patients with ATOLMCA have a dismal prognosis. Most patients present with cardiogenic shock, and a significant number develop cardiac arrest during the acute phase. Despite medical care, in-hospital mortality is high. Patients with left dominance may not even reach the hospital. Among survivors, long term outcomes are reasonable. Further studies are needed in order to improve the management and outcomes of patients with ATOLMCA.

Funding Acknowledgement

Type of funding sources: None.

Representativeness of EXPLORER-HCM trial and prevalence of eligibility criteria for Mavacamten in a nationwide cohort

Introduction

The EXPLORER-HCM trial evaluated the safety and efficacy of Mavacamten, a cardiac myosin inhibitor, in symptomatic obstructive hypertrophic cardiomyopathy (HCM). Mavacamten improved symptoms, exercise capacity and left ventricular outflow tract (LVOT) obstruction. However, the proportion of patients eligible for this therapy in real practice remains unclear.

Purpose

To determine the prevalence of eligibility criteria for Mavacamten and to describe the profile of patients complying with EXPLORER-HCM criteria in a nationwide cohort.

Methods

Cross-sectional study including all HCM patients enrolled in a European country-based nationwide registry. Presence of EXPLORER-HCM inclusion [≥18 years, obstructive HCM (LVOT gradient ≥50 mmHg), left ventricular ejection fraction (LVEF) ≥55%, New York Heart Association (NYHA) class II–III] and exclusion criteria [syncope or sustained ventricular tachycardia with exercise] were analyzed.

Results

Of 1042 patients included in this analysis (57.8% male, mean age at diagnosis 52 years, 39.6% obstructive HCM), 45 met the EXPLORER-HCM inclusion criteria and, after applying exclusion criteria, 30 patients were eligible for therapy with Mavacamten.

Eligible patients were all Caucasian, mostly female (63.3%), with a mean age at diagnosis of 58±14 years. All patients presented with heart failure symptoms, and were mostly in NYHA class II (83.3%); 4 patients (13.3%) presented with atrial fibrillation. In the baseline echocardiogram, mean LVEF was 68±9%; mean interventricular septum thickness was 20±4 mm; most patients presented with systolic anterior motion of the mitral valve (96.7%) and mitral regurgitation (96.7%). In cardiac magnetic resonance imaging evaluation, maximal wall thickness was 22±4 mm and 76.9% had late gadolinium enhancement. A pathogenic or likely pathogenic HCM gene variant was identified in 5 patients (MYH7 and MYBPC3 gene mutations).

In this group, 86.2% of patients were treated with beta-blockers and 34.5% with calcium channel antagonists. Only 1 patient was on Disopyramide. Septal reduction techniques were used in 43.3% of patients: alcohol septal ablation and septal myectomy were performed in 7 (23.3%) and 6 (20.0%) patients, respectively. Cardioverter-defibrillators were implanted in 2 patients for primary prevention of sudden cardiac death, and 6 patients received a pacemaker for bradycardia indications.

Conclusion

Specific therapies remain an unmet need in HCM. In this large nationwide cohort, only 2.9% of patients were eligible for therapy with Mavacamten according to EXPLORER-HCM criteria. Among patients complying with the study criteria, invasive septal reduction therapies were offered to a high proportion of patients. Further real-world data are warranted to estimate the proportion of HCM patients that will benefit from Mavacamten.

Funding Acknowledgement

Type of funding sources: None.

Mechanical circulatory support devices in left main occlusion: a multicenter study from 2008 to 2020

Introduction

Evidence of benefit in the use of mechanical circulatory support devices (MCS) in patients with acute myocardial infarction (AMI) is scarce. We aimed to evaluate the clinicalcharacteristics, prognosis and factors associated with the use of MCS in patients with AMI due to left main (LM) occlusion.

Methods

We performed a retrospective multicenter study of 128 consecutive patients with AMI with ≤12h of presentation with LM occlusion submitted to immediate reperfusion between January 1, 2008, until December 31, 2020 in three terciary hospitals of Portugal. Among this cohort, we divided patients into two groups according to the use of MCS devices.

Results

Regarding the baseline characteristics no statistically significant differences were found, except for the presence of cerebrovascular disease (2.9% in group with vs 16.9% in group without MCS, p=0.007) and peripheral artery disease (8.8% in group with vs 22% in group without MCS, p=0.037). We observed that the use of MCS devices was statistically different between the three centers (47.8%, 42%, 8.7%, p<0.001). No differences were found at presentation for ST-segment elevation vs non-ST segment elevation AMI (p=NS). The presence of cardiogenic shock (72.4% vs 45.8%, p=0.002), cardiac arrest (27.5% vs 23.7%, p=0.034) and more severe thrombolysis in myocardial infarction (TIMI) flow at presentation (55.1% vs 35.6%, p=0.015) were more frequent in group with MCS. The rate of 1-year cumulative mortality was high in both groups (31/59=52.5% in the group without vs 47/69=68.1%, p=NS). Also, no statistically significant differences were found in terms of survival, but we observed a trend to higher mortality in those who received MCS as Kaplan-Meier survival curves show (log rank=0.062). Finally, in multivariable analysis, older age [odds ratio (OR), 0.935; 95% CI, 0.87–0.99], the presence of diabetes (OR, 0.223; 95% CI, 0.056–0.88), peripheral artery disease (OR, 0.070; 95% CI, 0.009–0.566) and extra-hospitalar cardiac arrest (OR, 0.06; 95% CI, 0.007–0.543) were characteristics associated with lower odds of receiving MCS. Contrarily, male sex (OR, 5; 95% CI, 1–20.4) and the presence of cardiogenic shock (OR, 5.7; 95% CI, 1.42–23) were factors associated with higher use of MCS.

Conclusion

The use of MCS does not seem to modify prognosis in patients admitted withAMI due to left main occlusion. Only cardiogenic shock and male gender were predictors of MCS use.

Funding Acknowledgement

Type of funding sources: None.

Predictors of left ventricular dysfunction in hypertrophic cardiomyopathy: results from a nationwide registry

Introduction

Progression of hypertrophic cardiomyopathy (HCM) with incident left ventricular (LV) dysfunction (HCM-LVSD) is associated with poor prognosis and advanced heart failure (HF). Prevalence ranges from 5–10% in previous studies. Identification of predictors of adverse remodeling may improve risk stratification and prognostication in HCM.

Purpose

To identify predictors of HCM-LVSD in a nationwide cohort of HCM patients (pts).

Methods

Retrospective study including all HCM pts enrolled in a European country-based nationwide registry. HCM-LVSD group included pts with LV ejection fraction (LVEF) ≤50% at baseline and pts who developed LV dysfunction/dilated phenotype during follow-up. Multivariate logistic regression was performed to identify predictors of HCM-LVSD.

Results

1042 HCM patients (57.8% male, mean age at diagnosis 52 years) were included, of whom 81 (8%) belonged to the HCM-LVSD group. HCM-LVSD pts were mostly male (60.5%) and tended to be older at the time of diagnosis than those without LVSD (55 vs 52 years, p=0.054). HCM-LVSD pts were more often symptomatic at the index visit (84.1% vs 65.2%, p<0.001), with more functional impairment (New York Heart Association class III–IV: 18.5% vs 9.2%, p=0.021). Atrial fibrillation (21.3% vs 8.6%, p<0.001) and intraventricular conduction disturbances (28.6% vs 14.4%, p=0.002) were more prevalent in HCM-LVSD pts. HCM-LVSD pts had higher baseline left atrium (LA) volumes (52 vs 39 ml, p=0.001), lower LVEF (50 vs 67%, p<0.001) and higher rates of mitral regurgitation (79.0% vs 65.1%, p=0.011). Prevalence of obstructive HCM was lower in the HCM-LSVD group (25.3% vs 40.9%, p=0.007). Presence of late gadolinium enhancement (92.6% vs 74.6%, p=0.035) was more common in pts with LVSD. Baseline N-terminal pro–B-type natriuretic peptide was higher in HCM-LVSD (3839 vs 1281 pg/ml, p=0.027). There were no differences in the number and type of genetic variants between groups. In HCM-LVSD pts, implantation of cardioverter-defibrillators for secondary prevention was more frequent (28.6% vs 6.4%, p=0.002), as was the use of pacemaker (16.7% vs 7.0%, p=0.002). During a mean follow-up of 5.3±6.1 years, hospitalization for HF (50.0% vs 11.3%) and all-cause mortality (12.3% vs 2.9%, p<0.001) were more frequent in HCM-LVSD group.

After multivariate analysis, higher LA volume (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01–1.05, p=0.003) and nonobstructive HCM (OR 2.74, 95% CI 1.03–7.27, p=0.043) were independent predictors of HCM-LVSD.

Conclusions

In this large nationwide cohort of HCM pts, prevalence of LVSD was 8%, in line with existing literature. In this cohort, larger LA volumes and nonobstructive HCM predicted progression to HCM-LVSD.

Funding Acknowledgement

Type of funding sources: None.

Single stenting versus double stenting technique in true bifurcation coronary lesions

Introduction

The ideal treatment technique for coronary bifurcation lesions remains unknown. Although single-stenting strategy has been recommended by default, little evidence exists regarding clinical outcomes between single versus double-stenting in current practice.

Purpose

To compare procedural details and clinical outcomes between single vs double-stenting techniques in true bifurcation coronary lesions.

Methods

Retrospective study of all patients (pts) referred for percutaneous coronary intervention (PCI) of true bifurcation lesions between June 2018 and June 2020. Only Medina X,X,1 lesions were included. Pts were split in 2 groups: group 1 (single-stenting) and group 2 (double-stenting). Procedural details and clinical outcomes were assessed. Acute and long-term adverse events included procedural complications (a composite outcome of side branch occlusion, coronary iatrogenic dissection and type 4 acute myocardial infarction (AMI)) and a composite of cardiovascular death, AMI, stroke, re-restenosis and reintervention, respectively.

Results

A total of 118 pts were included, 74,6% male, mean age of 66,4±11 years.

Ninety-five pts (80,5%) were treated with single-stenting (G1) and 23 pts (19,5%) with double-stenting technique (G2). Both groups were well matched regarding baseline characteristics and clinical presentation. T and protrusion (TAP) and minicrush were the most frequent double-stenting techniques (43,5% and 21,7%).

G2 lesions mainly involved the left main (LM) and proximal left anterior descendent artery (LAD) (52,2%) and in G1 mid LAD (34,7%). LM lesions were more common in G2 (26,1% vs 8,4%; p=0,030). G1 had more lesions Medina 1,1,1 (75,8% vs 52,2%; p=0,025) and less Medina 0,1,1 (9,5% vs 30,4%; p=0,015). Proximal optimization technique and kissing balloon occurred more in G2 (p<0,05). G2 had more intravascular ultrasound guided PCI (p=0,046). Femoral access, heparin, contrast and radiation dose, and fluoroscopy time were higher in G2 (p<0,05). Acute adverse composite outcome was similar in both groups (G1 13% vs G2 14,3%; p=0,855).

Median follow-up was similar (G1 16,8±7,9 and G2 19,7±8,8 months; p=0,127). G1 had less occurrence of long-term adverse composite outcome (7,4% vs 26,3%; p=0,032). Excluding interventions in LM, G2 had more significant incidence of acute events (20% vs 2,6%; p=0,028), and higher rate of long-term adverse events (20% vs 4,2%; p=0,056). In interventions of the LM only, no differences were noticed in acute and long-term composite events between groups.

Conclusions

Double-stenting techniques in true coronary bifurcation lesions included more often LM lesions and were complex procedures requiring frequently intracoronary imaging. Although acute adverse events were similar to those of single-stenting, long-term adverse outcomes were more frequent in double-stent group, except for LM lesions.

Funding Acknowledgement

Type of funding sources: None.

Staging cardiac damage in aortic valve disease: one size fits all?

Background

Nowadays, in patients with aortic regurgitation (AR), aortic valve surgery is indicated when severe and symptomatic or those with depressed LVEF. However, clinical outcomes of patients with significant aortic regurgitation are not influenced by these factors only. Recently, a new staging system for severe aortic stenosis has been proposed by Généreux on the basis of the extent of anatomic and functional cardiac damage. If this model could be applicable to an unselected significant AR population has not been tested.

Purpose

The aim of our study was to evaluate the prevalence of the different stages of extra-aortic valvular cardiac damage by the application of Généreux staging and its impact on prognosis in a large, real world cohort of significant AR patients.

Methods

This study retrospectively analysed the clinical, Doppler echocardiographic and outcome data in patients with grade III or greater AR between January 2014 and September 2019. According to the extent of cardiac damage on echocardiography, patients were classified as Stage 0 (no cardiac damage), Stage 1 (left ventricular damage), Stage 2 (mitral valve or left atrial damage), Stage 3 (tricuspid valve or pulmonary artery vasculature damage) or Stage 4 (right ventricular damage). Exclusion criteria were severe aortic stenosis and previous valve repair or replacement. The primary end-point was all-cause mortality.

Results

A total of 572 patients, aged 70.1±13.9 years, 294 (51.3%) men were enrolled. One third of patients were in NYHA I. Based on the proposed classification, 82 patients (14.3%) were classified in stage 0, 130 (22.7%) in stage 1, 276 (48.2%) in stage 2, 68 (11.8%) in stage 3 and 17 (3.0%) in stage 4. Median follow-up time was 3.3±1.9 years. There was a progressive increase in mortality rates according to staging: 8.5% in stage 0, 10.8% in stage 1, 24.9% in stage 2, 42.6% in stage 3 and 52.9% in stage 4 (p<0.001). On multivariable analysis, the extent of cardiac damage was independently associated with excess mortality (HR 1.69, 95% CI 1.29 to 2.21)

Conclusion

Our study demonstrated that this new staging system studied for aortic stenosis also provides increased prognostic value to patients with significant aortic regurgitation. This staging system can be helpful to identify the degree of extra-aortic valvular cardiac damage and to optimize the time of valvular intervention. Further prospective studies are needed to confirm the benefit of the applicability of this model in clinical practice.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Centro Hospitalar Vila Nova de Gaia / Espinho Distribution of stages of cardiac damageSurvival analysis according to stage

Prognostic impact of coronary artery disease severity and revascularization in TAVI patients

Background

Coronary artery disease (CAD) is highly prevalent in patients with severe aortic stenosis. In patients who undergo surgical aortic valve replacement, the presence of CAD and the need for CABG adversely influences short- and long-term outcomes. However, the impact of concomitant CAD and its revascularization in patients undergoing transcatheter aortic valve implantation (TAVI) is still a matter of debate.

Purpose

The aim of this study was to evaluate the prognostic impact of CAD severity in 1-year all-cause mortality of patients undergoing TAVI and whether prior complete or incomplete reasonable revascularization can improve prognosis after TAVI.

Methods and results

Retrospective analysis of a total of 575 patients (51,3% female, mean age 79,7±7,7 years) who underwent TAVI from August 2007 to November 2018. 50,3% of patients had significant CAD (at least one stenosis >50%) which 54,2% of these had history of prior revascularization (64,8% complete or incomplete reasonable revascularization and 35,2% incomplete revascularization).

Pre-TAVI CAD severity was defined by the SYNTAX Score (SS) and reasonable revascularization by the residual SYNTAX Score (rSS). Patients without history of revascularization were stratified into 3 groups: no CAD (SS=0); nonsevere CAD (SS between 1 and 22); and severe CAD (SS ≥23); Patients who had undergone revascularization prior to TAVI were separated into 2 categories based on their residual SS: complete or incomplete reasonable revascularization (rSS<8) and incomplete revascularization (rSS≥8). The primary end point was an all-cause mortality. 1 year, patients with severe CAD had significantly higher rates of mortality (no CAD: 9,8%, nonsevere CAD: 12,6%, severe CAD: 38,9%; P=0.001) without significant differences between patients with no CAD and nonsevere CAD (p=1,00). Patients with high rSS had significantly higher rates of mortality comparing to no CAD or rSS<8 (no CAD: 9,8%, rSS<8: 8,6%; rSS≥8: 28,0%, p=0.001).

Conclusions

In our study, only the presence of severe CAD (SS≥23) prior to TAVI was associated with increased 1-year all-cause mortality. In patients with previous history of revascularization, a complete/reasonable revascularization (lower rSS) was associated with lower long-term mortality, which may attenuate the association of severe CAD and mortality and therefore improve the prognosis of these patients.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Centro Hospitalar Vila Nova de Gaia / Espinho Figure 1. Prognostic Impact of CAD severityFigure 2. Prognostic Impact of Revascularization

Feasibility of coronary angiography after TAVR

Background

The prevalence of coronary artery disease (CAD) is high among patients with severe aortic stenosis who undergo transcatheter aortic valve replacement (TAVR).

Indications for TAVR are now expanding to younger and lower risk patients. During their lifetime, these patients will be at risk of developing CAD and it is expected an increase in coronary angiography and percutaneous coronary intervention (PCI). Aortic prosthesis, particularly if in supra-annular position, may pose important technical difficulties in coronary re-engagement after TAVR.

Purpose

To evaluate the feasibility to reengage the coronary ostia after TAVR, describe complications and compare technical differences between coronary procedures performed before and after TAVR.

Methods

Retrospective analysis of 714 patients submitted to TAVR from August 2007 to December 2019. Patients who needed coronary angiography after TAVR were selected.

The primary endpoint was the rate of successful coronary ostia cannulation after TAVR, defined by the possibility to selectively cannulate and inject both coronary ostia.

Secondary endpoint was complications associated with coronary catheterization after TAVR.

Results

Among 714 patients, 25 (3.5%) patients were submitted to a total of 28 coronary angiography after TAVR. 14 patients were male (56%), mean age 78.2±6.2 years and 9 (36%) had history of previous coronary revascularization.

From the 28 coronary angiographies (balloon-expandable Edwards-Sapien n=11, 44%; self-expandable CoreValve n=10, 40%; Portico n=2, 8%; Symetis n=2, 8%), 25 (89%) met the primary endpoint. Only three was semiselective (Symetis, CoreValve Evolut R and CoreValve TAVR in TAVR), with impossibility to cannulate both coronary arteries, right coronary artery and left coronary artery, respectively. 13 (46%) patients had also indication for PCI and all were successfully performed (Edwards-Sapien n=4, 31%; CoreValve n=6, 46%; Portico n=2, 15%; Symetis n=1, 8%). The main indications for coronary angiography was chronic coronary syndrome (n=12, 43%) and acute coronary syndrome without ST segment elevation (n=7, 25%). Circumflex artery was the most frequently treated vessel (n=6), followed by left anterior descending artery (n=4), right coronary artery (n=3) and left main (n=2).

There were no complications reported during or post-procedure. Comparing coronary angiographies before and after TAVR, there were no significant differences regarding arterial access site, catheter diameter, fluoroscopy time and quantity of contrast used in coronary angiography.

Conclusion

Although the need for coronary angiography was rare in patients after TAVR, selective diagnostic coronary angiographies were possible in 89% (25/28) and PCI was feasible in all patients in whom it was indicated, without any reported complications.

Further prospective studies are needed to confirm the great feasibility of performing coronary angiography after TAVR.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Centro Hospitalar Vila Nova de Gaia / Espinho

Outcomes and predictors of clinical response after upgrade to resynchronization therapy

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND

 Upgrade to  resynchronization therapy (CRT) is common practice in Europe. However, patient selection remains a challenge. Data regarding predictors of response to upgrade is currently lacking.

AIM

To identify predictors of clinical response after upgrade to CRT.

METHODS

Single-center retrospective study of consecutive patients submitted to upgrade to CRT (2007-2018). Patients underwent clinical and echocardiographic (echo) evaluation at baseline, 6-months and 1-year. Major adverse cardiac events (MACE) included hospitalization for heart failure (HF) or all-cause mortality. Clinical response was defined as New York Heart Association (NYHA) class improvement without MACE in the 1st year of follow-up (FU). Left ventricle end-systolic volume reduction of >15% designated echo response. Multivariate logistic regression was performed to identify predictors of clinical response to CRT.

RESULTS

Fifty-six patients submitted to upgrade to CRT (80.4% male, mean age 70.0 ± 9.6 years) were included; 43 patients (78.2%) previously had a pacemaker and 12 (21.8%) had a defibrillator device.  Most patients had non-ischemic HF (67.9%), with a mean baseline left ventricle (LV) ejection fraction of 27.9 ± 6.4%. Indications for upgrade were mainly pacemaker dependency or pacing-induced LV dysfunction (76.6%) and de novo left bundle branch block (23.4%).

Thirty-one (59.3%) patients were clinical responders. MACE occurred in 37.5% of patients; 28.6% were hospitalized for HF and 13% died during the 1st year of FU. Clinical responders had a lower rate of atrial fibrillation (AF) (46.9% vs. 53.1%, p=.025) and a higher rate of pacemaker rythm prior to upgrade (80.6% vs 47.6%, p=.013). Among responders, the previous device was more frequently a pacemaker (87.5% vs 61.9%, p=.029), and the new device a CRT-P (81.2% vs 54.5%, p=.035). HF etiology did not differ between responders and non-responders.

Multivariate analysis identified absence of AF (odds ratio [OR] 4.4, 95% confidence interval [CI] 1.1-17.6, p=.037), CRT-P (OR 5.7, 95% CI 1.3-25.8, p=.022) and quadripolar lead implant (OR 3.8, 95% CI 1.3-25.8, p=.024) as predictors of clinical response in upgraded patients.

CONCLUSIONS

In this cohort, absence of AF, implantation of CRT-P and use of a quadripolar lead predicted clinical response to upgrade to CRT. Larger studies are warranted to tailor selection of patients for upgrade procedures.

Superresponse to cardiac resynchronization therapy: clinical outcomes and predictors

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND

Resynchronization therapy (CRT) reduces morbidity and mortality in selected patients with heart failure with reduced ejection fraction (HFrEF). Patients that experience significant reverse remodelling and left ventricular (LV) ejection fraction (LVEF) improvement have been called "superresponders".

AIM

To describe a cohort of superresponders and identify predictors of superresponse to CRT.

METHODS

Single-center retrospective study of consecutive patients submitted to CRT implantation (2007-2018). Patients underwent echocardiographic (echo) assessment at baseline, 6-months and 1-year. Superresponse was defined as LVEF≥50% during the 1st year of follow-up (FU). Major adverse cardiac events (MACE) included heart failure hospitalization or all-cause mortality. Multivariate logistic regression was performed to identify predictors of superresponse. Survival analysis with Kaplan-Meier method and Log-rank test was performed to compare outcomes between superresponders and non-superresponders.

RESULTS

295 CRT patients (70.5% male, mean age 67 ± 11 years) were included. Fifty-nine (21.4%) patients were superresponders. Superresponders were more often female (42.4% vs 25.8%, p=.021), tended to be older (69.6 vs 66.7 years, p=.054) and had lower rates of coronary disease (17.2% vs 32.9%, p=.032), atrial fibrillation (20.3% vs 38.0%, p=.018), valve disease (13.6% vs 30.0%, p=.018) and chronic kidney disease (6.9% vs 26.0%, p=.003). Superresponders had higher rates of non-ischemic HF (88.1% vs 69.1%, p=.006) and were more often implanted with CRT-P (69.5% vs 37.8%, p<.001). HFrEF medication did not differ between groups.

Superresponders had lower baseline LV end-systolic volumes (115.5 vs 166.2 ml, p<.001) and N-terminal pro B-type natriuretic peptide (NT-proBNP) values (1232.6 vs 5252 pg/ml, p<.001). Baseline QRS duration did not differ (171.7 vs 171.3 ms, p=.883). During a median FU of 3 ± 5 years, there were no differences in terms of ventricular arrythmias (5.3% vs 6.8%, p=.913) or appropriate defibrillator therapies (1.8% vs 6.8%, p=.147) between groups. In addition to LVEF improvement (53.7% vs 35.3%, p<.001), superresponders also showed higher tricuspid annular plane systolic excursion values (22.1 vs 19.8 mm, p=.004) during FU. MACE occurred less frequently (Log-rank test, p=.003) and all-cause mortality (Log-rank test, p < 0.001) was lower in superresponders.

Multivariate analysis identified female gender (odds ratio [OR] 5.7, 95% confidence interval [CI] 1.03-31.73, p=.045), older age (OR 1.1, 95% CI 1.02-1.24, p=.017) and lower baseline NT-proBNP (OR 0.9, 95% CI 0.99-1.00, p=.011) as independent predictors of superresponse to CRT.

CONCLUSION

In superresponders, in addition to a significant improvement in LVEF, we observed an improvement in right ventricular function. As expected, MACE and all-cause mortality were lower. Female gender, older age and lower baseline NT-proBNP predicted super-response to CRT.

Comparison of de novo and upgrade to resynchronization therapy: a propensity-score matched analysis

Background

Upgrade to resynchronization therapy (CRT) from conventional pacemaker (P) or defibrillator (D) is common practice in Europe. However, guidelines (GL) are discordant: Pacing GL give a class I recommendation, while Heart Failure (HF) GL provide a class IIb indication. Previous studies suggested worse outcomes in upgraded patients (pts).

Aim

To compare response rate and clinical outcomes in a cohort of pts receiving de novo or upgrade to CRT.

Methods

Single-center retrospective study of consecutive pts submitted to CRT implantation (2007–2017). Major adverse cardiac events (MACE) included HF hospitalization (HHF) or all-cause mortality. Clinical response was defined as New York Heart Association class improvement without MACE in the first year of follow-up (FU). Left ventricle end-systolic volume reduction of >15% denoted echocardiographic (echo) response. Survival analysis with Kaplan-Meier method and Log-rank test was performed. Propensity-score matching (PSM) analysis was made to adjust for possible confounder variables.

Results

230 CRT recipients (70.9% male, mean age 67±11 years, 71.5% non-ischemic cardiomyopathy, 39.6% CRT-P) were included, of whom 46 (20%) underwent an upgrade. Upgraded pts were older (69.8 vs 65.9 years, p=0.015), with higher rates of permanent atrial fibrillation (37.0% vs 12.7%, p=0.001), moderate to severe valve disease (45.7% vs 22.3%, p=0.002), chronic kidney disease (37.0% vs 17.2%, p=0.005) and treatment with mineralocorticoid receptor antagonists (79.1% vs 52.0%, p=0.002). They were more likely to receive CRT-P (65.2% vs 33.2%, p<0.001) and CRT-D were more often implanted for secondary prevention (60.0% vs 17.9%, p=0.001). No differences emerged in procedural complications, clinical (74.4% vs 71.4%, p=0.712) or echo (66.7% vs 69.7%, p=0.822) response rates.

During a median FU of 3±4 years, all-cause mortality was similar among groups (Log Rank test, p=0.522, unadjusted hazard ratio [HR] 1.25, confidence interval [CI] 95% 0.62–2.49, p=0.534). There was a statistical tendency for higher MACE rate in the upgrade group (Log Rank test, p=0.064, HR 1.66, CI 95% 0.95–2,91, p=0.076). No differences were found in lead dislodgement (10.9% vs 7.1%, p=0.368) or endocarditis (2.2% vs 4.3%, p=0.692) rates.

PSM analysis identified 88 matched pairs (46 upgrade/42 de novo pts). In this cohort, all-cause mortality (Log Rank test, p=0.77, HR 0.89, CI 95% 0.39–2.03, p=0.78) and MACE (Log Rank test, p=0.36, HR 1.38, CI 95% 0.68–2.81, p=0.37) were comparable between groups [graph no. 1].

Conclusion

Upgrade to CRT was similar to de novo implantation in terms of complications and clinical and echo response, in this cohort. The risk for MACE and mortality was also comparable.

Graph 1

Funding Acknowledgement

Type of funding source: None

Early discharge after TAVI: should we still be afraid of conduction disturbances?

Introduction

Conduction disturbances (CD) after TAVI remains the most frequent complication of the procedure, frequently increasing the length of hospital stay. A lack of consensus exists regarding in-hospital management of CD post-TAVI.

Purpose

To evaluate if an early discharge (ED) protocol could be safely implemented in patients (pts) with CD post-TAVI.

Methods

Retrospective study of all pts submitted to TAVI between 2016 and 2018. Pts with prior permanent pacemaker (PP) and non-transfemoral approach were excluded. ECG data before, immediately after the procedure and at day 3 post-TAVI were collected, and continuous telemetry monitoring was recorded. We applied a recently proposed ED algorithm (adapted from Management of Conduction Disturbances Associated With Transcatheter Aortic Valve Replacement - JACC Scientific Expert Panel; JACC 2019; 74(8):1086–106) to identify which pts could have been candidates for ED. ED was defined as discharge in the first 72 hours (h) after the procedure. We evaluated if an ED strategy would have been safe at 1-year follow-up (FUP), as defined by the absence of need for PP, syncope and mortality.

Results

242 pts were included, 44,8% males, mean age 80,4 years, mean Euroscore II 5,4 and the majority implanted a self-expandable prosthesis (64,1%). Mean hospital stay after TAVI was 7,7 days. The most frequent CD after TAVI were: new onset left bundle brunch block (36%) and high degree atrioventricular block (HAVB) (16,3%). During hospital stay 21,6% needed PP, mainly because of HAVB (mainly implanted in the first 72h).

According to the proposed algorithm, 70,7% of our pts were ED-candidates. ED-candidates had lower prevalence of predilation (18,5% vs 36,8%, p=0,008) with no significant differences between type of prosthesis or baseline ECG. ED-candidates had smaller PR interval post-TAVI (184,5 vs 202,5 ms, p=0,044) and smaller PR and QRS at 72h (p<0,001 in both).

At 1-year FUP, only 2,3% of ED-candidates needed a PP (vs 37,7% non-ED, p<0,001). It is noteworthy that in those ED-candidates who needed a PP during FUP, the percentage of ventricular pacing was less than 2% at 6 months. In the FUP period, 3,2% of ED candidates presented at the ER because of syncope, with no significant differences to non-ED pts. No differences between groups were found in 30-days and 1-year ER presentation because of syncope or all-cause mortality.

Conclusions

According to the proposed algorithm for ED in pts with CD post-TAVI, pts with specific ECG characteristics and without rhythm events during continuous telemetry monitoring can be early discharged with long-term safety.

Funding Acknowledgement

Type of funding source: None

Behavioral asymmetries and neurochemical changes after unilateral lesions of tuberomammillary nucleus or substantia nigra

Previous studies in the rat have shown that the hypothalamic tuberomammillary nucleus, the major source of neuronal histamine, is related to mechanisms of learning, memory, reinforcement, and functional recovery. These functional relationships were found to be partly lateralized. Therefore, we decided to analyze whether unilateral ibotenic acid lesions aimed at this brain region would acutely lead to asymmetries in open-field behavior, and whether they would affect the biogenic amines dopamine and serotonin in the neostriatum, hippocampus, and tectum. We compared this manipulation with unilateral 6-hydroxydopamine lesions of the substantia nigra pars compacta and with unilateral ibotenic acid lesions of the substantia nigra pars reticulata. These lesions were investigated because all three brain areas are anatomically linked to the neostriatum, are related to the neurotransmitters dopamine and serotonin, and play a role in behavioral asymmetry and functional recovery. In support of previous findings, our data show that 6-hydroxydopamine lesions of the substantia nigra pars compacta led to an ipsiversive asymmetry in turning and scanning. Ibotenic acid lesions of the adjacent pars reticulata led to contraversive turning, whereas thigmotactic scanning was reduced bilaterally. In contrast, ibotenic acid lesions of the tuberomammillary nucleus did not affect turning, but led to an ipsilateral asymmetry in scanning. Neurochemically, the 6-hydroxydopamine lesion was mainly characterized by the well-known ipsilateral neostriatal dopamine depletion and increased residual dopamine activity. In hippocampus and tectum, these transmitters were not specifically affected, except for an asymmetry of serotonin in the superior colliculus. The ibotenic acid lesions of the pars reticulata did not deplete neostriatal dopamine, indicating that they spared the dopaminergic output of the substantia nigra. In contrast, they affected dopaminergic and serotonergic measures in the colliculi, which may be due to damage of the nigral GABAergic projection to this brain area. In animals with unilateral ibotenic acid lesions of the tuberomammillary nucleus, several markers of dopaminergic and serotonergic activity were increased in the neostriatum, tectum, and hippocampus. This effect may have been due to the loss of inhibition otherwise provided by the wide-ranging histaminergic output of the tuberomammillary nucleus. These results are discussed with respect to the major outputs of the three brain areas, their potential impacts on neurotransmitters in their projection sites, and their role in behavioral asymmetry.

A neuropharmacological study of the periventricular neural substrate involved in flight

This paper reviews results obtained in experiments concerning the neurochemical characteristics of the substrate involved in the control of flight reactions and the induction of aversive effects in the rat. These experiments investigated the behavioural effects produced by microinjecting into the periaqueductal grey matter (PAG) or the medial hypothalamus (MH) compounds known to interfere with the functioning of some neurotransmitter systems known to exist in these structures. The data obtained show that: the activity of the substrate involved in the production of flight reactions is tonically inhibited by the release of GABA (gamma-aminobutyric acid); the behavioural reactions produced by microinjecting GABA antagonists can be clearly distinguished, depending on whether such drugs were injected into the PAG or the MH, despite the fact that jumps were produced from either level; behavioural effects, comparable to some extent to those produced by microinjections of GABA antagonists, can be obtained by injecting drugs which act on non-GABAergic neurochemical substrates, namely opioidergic or cholinergic systems; and behavioural effects, comparable to those produced by injecting GABA antagonists into the PAG, can be obtained by injecting such drugs into various sites located in other parts of the tectum such as the inferior colliculus or adjacent structures.