TAVI via alternative access routes: patient selection and 10-year center experience

Background

Femoral access is considered the gold standard for transcatheter aortic valve implantation (TAVI). However, this route might be precluded due to the presence of tortuosity, small vessel diameter and/or peripheral artery disease. We aimed to investigate TAVI through an alternative access (AA), focusing on the selection criteria and clinical outcomes compared to the femoral route (TF).

Methods

We conducted an all-comers longitudinal single-centre prospective registry in whom a TAVI was performed. The feasibility, safety and efficacy of TAVI by means of an access route other than standard TF was assessed, according to the VARC-2 criteria. The prospective surgical criteria used at our institution to accept an AA route were: a) TF deemed inappropriate; b) acceptable haemorrhagic risk; c) acceptable general anaesthesia risk; and d) adequate anatomy and diameter within acceptable range (subclavian, axillar, transaortic) or e) age <85 years and non-frail patient (transapical). The primary endpoint was all-cause death at 1-year.

Results

From 2008 to 2018, there were 548 patients submitted to TAVI [median age 84 (79–87) years, males 45.4%]. An AA route was used in 100 patients (79 trans-apical, 9 trans-aortic, and 12 trans-subclavian), with a decreasing rate over follow-up (−11% per year). Compared to TF, these patients were younger [80 (77–84) vs. 85 (80–87) years; p<0.001) with a similar baseline surgical risk as per EuroSCORE II [5.1 (3.3–9.0) vs. 4.7 (3.3–7.0); p=0.410). AA patients presented a higher burden of atherosclerotic disease, namely coronary (54.0 vs. 41.3%; p<0.001) and peripheral artery disease (35.0 vs. 16.5%, p<0.001) despite a lower number of other comorbidities (e.g. glomerular filtration rate <50mL/min: 53.1 vs. 64.8%; p=0.030). Left ventricular ejection fraction (56±13 vs 55±12%; p=0.203) and aortic stenosis severity (e.g. valve area: 0.70±0.19 vs. 0.67±0.18cm2; p=0.302) were similar between groups. Haemorrhagic events (minor or major) following TAVI were less often documented in the AA group (11.0 vs 21.7%; p=0.015), contrasting with de novo atrial fibrillation (18.5 vs 7.6%; p=0.048). Overall, 67 patients met the primary endpoint (18.8 vs 16.2%; p=0.584). After adjusted multivariate analysis, the independent predictors of one-year mortality did not include the TAVI access route.

Conclusion

In the first 10 years of experience, 1 in every 6 patients was treated with a TAVI by means of an AA, most often trans-apically initially and, nowadays, via a trans-subclavian approach. The use of meticulous prospective selection criteria seems to explain the one-year similar results, regardless of the access route.

Funding Acknowledgement

Type of funding sources: None.

Predicting pacemaker dependency after TAVI with pre-procedural MSCT

Background and aim

High degree conduction disturbances is a burdensome complication of transcatheter aortic valve implantation (TAVI). There is limited data whether such disorders are permanent or reversible. Anatomic surrogates, such as membranous septum [MS, a distance marker from aortic annulus to His-bundle surge] and calcium distribution within aortic valve have been associated with pacemaker (PM) implantation. The aim of our study was to assess predictors of long-term pacemaker dependency following TAVI.

Methods

Single center prospectively included patients that underwent pacemaker implantation following TAVI (March 2017 to September 2020). Patients who were lost to follow up, with bicuspid aortic valve, previously implanted PM and non-available or low quality MSCT exam were excluded. On MSCT, MS length was measured on modified coronal view, the aortic-valvular complex (AVC) was characterized by leaflet sector and calcium distribution was assessed on a J-score threshold of 850-Hounsfield units. Pacemaker dependency was assessed by reducing ventricular pacing to 30 bpm and defined by subsequent complete AV dissociation in patients in sinus rhythm or an escape rhythm <50 bpm in atrial fibrillation, in addition of >90% pacing percentage since implantation.

Results

From the 352 patients with inclusion criteria, 67 underwent PM implantation (19%) and 55 included in the analysis (male 33.9%, median age=85) (Figure). Median time for pacemaker implantation was 3 days [interquartile range (IQR) 3–5 days], mostly due to complete auriculo-ventricular block (76.4%, N=42). PM dependency occurred in 14 out of 55 (25.5%) patients at mean follow up of 500±363 days. Patients with PM dependency tended to have deeper implantation depth, (6.2 mm vs 5.5 mm, p=0.096) and a significantly shorter MS (5.8 mm vs 6.8 mm, P-value = 0.031) (Table). Increasing MS length was independently associated with a lower risk of PM dependency [odds ratio (OR) 0.58 per mm; 95% CI: 0.35–0.98, p=0.04] regardless prosthesis choice. MS length under 5 mm had 97.6% specificity (95% CI: 87.1–99.9) and 85.7% positive predictive value for pacemaker dependency (AUC=76.7; 95% CI 63.3–87).

Conclusion

Our findings highlight the importance of MSCT-derived MS length to stratify the risk of long term need for pacemaker. Patients with short MS (<5mm) in addition to conduction abnormality following TAVI had a high likelihood of PM dependency on the long term and should be considered for prompt PM implantation.

Funding Acknowledgement

Type of funding sources: None.

Validation of a novel framework defining the acceptable standard of care for heart failure with reduced ejection fraction

Background

In heart failure with reduced ejection fraction (HFrEF), uptitration of neurohormonal antagonists to trial-proven doses shown to reduce mortality is challenging and seldomly achieved in clinical practice. A major reason for underdosing of these agents is the lack of a clear description of what constitutes an acceptable standard of care in HFrEF. To address this limitation, a novel framework for describing the physician adherence to evidence-based treatment was recently proposed. The aim of our study was to evaluate and validate the proposed framework in a real-world population of patients with HFrEF.

Methods

A cohort of patients with HFrEF, defined as left ventricular ejection fraction (LVEF) <40%, under treatment with neurohormonal antagonists for at least 3 months were retrospectively identified at a tertiary hospital's Heart Failure Clinic. Demographic, clinical, echocardiographic and treatment data were assessed. Patients were divided in three strata for each neurohormonal antagonist, according to the proposed framework: Status I – patients receiving target doses or the highest tolerated dose; Status II – use of subtarget doses for reasons unrelated to clinically important intolerance; and Status III – not receiving the drug at any dose. The prognostic value of each strata was assessed for all-cause mortality.

Results

A total of 408 patients (mean age 68±12 years, 78% male, 63% ischemic etiology) were included. The median LVEF was 31% (IQR 25–36) and most patients were in NYHA class II or III [210 (51.5%) and 163 (40%), respectively]. Medical therapy is described in Table 1. During a median follow-up of 3.3 years (IQR 1.4–5.6), 210 patients died. On univariable analysis, achieving Status I of beta-blocker (BB) therapy (HR: 0.50; 95% CI: 0.32–0.81; P=0.004) or ACEi/ARB (HR: 0.56; 95% CI: 0.36–0.86; P=0.012) was associated with reduced all-cause mortality. The mortality of patients in Status II of BB or ACEi/ARB was similar to the mortality of those not receiving the drug (HR for BB: 0.90; 95% CI: 0.53–1.52; P=0.69 and HR for ACEi/ARB: 0.71; 95% CI: 0.42–1.18; P=0.182) – figure 1. Achieving Status I of BB remained independently associated with reduced mortality after adjustment for several clinical and echocardiographic confounders (n=13) (adjusted HR: 0.59; 95% CI: 0.35–0.98; P=0.041).

Conclusions

In this real-world population of patients with HFrEF, the vast majority of patients were in Status I of BB and ACEi/ARB therapy. Achieving Status I of BB therapy seems to be associated with reduced mortality, even after adjustment for several markers of disease severity, highlighting the need for uptitration of medical therapy to maximal tolerated doses according to trial-proven regimens.

Funding Acknowledgement

Type of funding sources: None.

Cardiovascular disease in an intensive care unit: patterns of an often fatal omen

Background

Care for the critically ill patient with Cardiovascular Disease (CVD) requires a unique management approach, as the theoretical critical threshold for decompensation is lower and inherent adaptive mechanisms may be compromised. We aimed to characterize the prognostic impact of CVD in patients admitted to an Intensive Care Unit (ICU).

Methods

We performed a cohort study of consecutive patients admitted to an ICU from January to December 2019. Patients were stratified as follows: (1) established CVD – presence of either atrial fibrillation, heart failure, coronary artery disease and/or peripheral artery disease; (2) at higher risk of CVD – known arterial hypertension, dyslipidemia, diabetes mellitus and/or current smoking, in the absence of established CVD; and (3) at lower risk of CVD – i.e. none of the above. The co-primary endpoints were all-cause death in ICU and death during index hospitalization.

Results

During 2019, there were 334 admissions in ICU, comprising a total of 296 patients (mean age 67±15 years, 58.1% male). Overall, 69 (23.3%) and 108 (36.5%) died in ICU and during index hospitalization, respectively. Compared to patients at lower risk of CVD, those at higher CVD risk or with established CVD had markers of more severe disease, as noted by higher risk scores (e.g., SAPS-II 35.0±20.0 vs. 43.5±22.3 vs. 52.6±20.0; p<0.001), higher rates of mechanical ventilation (41.5 vs. 57.3 vs. 63.9%; p=0.020), shock during ICU stay (34.0 vs. 52.7 vs. 66.9%; p<0.001) and acute kidney injury (26.4 vs. 35.5 vs. 57.9%; p<0.001), respectively, as well as higher death rates in ICU (5.7 vs. 21.8 vs. 31.6%; p=0.001) and index hospitalization (9.4 vs. 37.3 vs. 46.6%; p<0.001). In multivariate analysis, adjusted for age and cause of admission, established CVD independently predicted the risk of all-cause death in ICU (HR: 2.084; 95% CI: 1.136–3.823; p=0.018) and during index hospitalization (HR 1.712; CI: 1.009–2.889; p=0.046). The analysis for the group of patients at higher risk of CVD yielded similar results to the abovementioned.

Conclusion

Roughly 4 in every 5 patients admitted in ICU were at risk of or had established CVD. The presence of either of the above independently predicted a two- to three-fold higher risk of death during hospitalization. Our findings emphasize the considerable burden of CVD in ICU and underscore the importance of comprehensive management of the complex critically ill patient.

Funding Acknowledgement

Type of funding sources: None.

Incremental prognostic value of worsening renal function parameters in addition to the GRACE score in patients with acute coronary syndrome

Background

Baseline renal function, one of the parameters included in the GRACE score, has prognostic relevance in patients admitted for acute coronary syndrome (ACS).

Purpose

The aim of this study was to compare different worsening renal function (WRF) parameters during hospitalization for ACS and their impact on all-cause mortality. Furthermore, we aimed to assess if these parameters had any incremental prognostic value in addition to the GRACE score.

Methods

We conducted a single-center retrospective study enrolling consecutive patients admitted for ACS from January 2016 to December 2018. Estimation of glomerular filtration rate (eGFR) for each patient was calculated based on the CKD-EPI formula. WRF during hospitalization was assessed by means of: serum creatinine (sCr) elevation ≥0,3mg/dL, duplication of the sCr value or maximum sCr value ≥2,0mg/dL.

Results

A total of 555 patients were included (65±13 years old, 72% male). Overall, 402 (72%) had hypertension, 167 (30%) were diabetic, 88 (16%) had left ventricular ejection fraction <40%. Mean GRACE score was 102.7±29.1 and median sCr at baseline was 0.83 mg/dL [0.70; 0.97]. Median length of hospitalization was 4 days [2; 10] and the mean follow-up of 963 days.

Baseline eGFR showed significant correlation with mortality during follow-up (HR 0.742 [95% CI 0.691–0.797] per 10 mL/min/1.73m2 increase in eGRF). Moreover, all WRF parameters showed significant association with all-cause mortality during follow-up on a univariate analysis - p<0,001 (Table 1). Elevation of sCr ≥0,3 mg/dL during hospitalization was the most frequent WRF parameter (210 patients - 38%) and the most sensitive parameter to predict our endpoint, occurring in 56 patients who died during follow-up (sensitivity 66.7%). Both duplication of sCr and absolute sCr ≥2,0mg/dL during hospitalization showed a lower prevalence; however, the majority of patients with one of these findings died during follow-up (51,4% and 68,5%, respectively).

On a multivariate Cox regression analysis, adjusted for the GRACE score, all individual WRF parameters remained independently associated with all-cause mortality during follow up (Table 2).

Conclusion

Worsening renal function has significant prognostic impact in patients admitted for ACS. Identification of these parameters during hospitalization adds significant value to the prognostic stratification of the GRACE score.

Funding Acknowledgement

Type of funding sources: None.

Ventricular tachycardia ablation in nonischemic cardiomyopathy

Introduction

Catheter ablation outcomes for drug-resistant ventricular tachycardia (VT) in nonischemic cardiomyopathy (NICM) are suboptimal when compared to ischemic cardiomyopathy. We aimed to analyse the long-term efficacy and safety of percutaneous catheter ablation in this subset of patients.

Methods

Single-center observational retrospective registry including consecutive NICM patients who underwent catheter ablation for drug-resistant VT during a 10-year period. The efficacy endpoint was defined as VT-free survival after catheter ablation, while safety outcomes were defined by 30-days mortality and procedure-related complications. Independent predictors of VT recurrence were assessed by Cox regression.

Results

In a population of 68 patients, most were male (85%), mean left ventricular ejection fraction (LVEF) was 34±12%, and mean age was 58±15 years. All patients had an implantable cardioverter-defibrillator. Twenty-six (38%) patients underwent epicardial ablation (table 1). Over a median follow-up of 3 years (IQR 1–8), 41% (n=31) patients had VT recurrence and 28% died (n=19). Multivariate survival analysis identified LVEF (HR= 0.98; 95% CI 0.92–0.99, p=0.046) and VT storm at presentation (HR=2.38; 95% CI 1.04–5.46, p=0.041) as independent predictors of VT recurrence. The yearly rates of VT recurrence and overall mortality were 21%/year and 10%/year, respectively. No patients died at 30-days post-procedure, and mean hospital length of stay was 5±6 days. The complication rate was 7% (n=5, table 1), mostly in patients undergoing epicardial ablation (4 vs 1 in endocardial ablation, P=0.046).

Conclusion

LVEF and VT storm at presentation were independent predictors of VT recurrence in NICM patients after catheter ablation. While clinical outcomes can be improved with further technical and scientific development, a tailored endocardial/epicardial approach was safe, with low overall number of complications and no 30-days mortality.

Funding Acknowledgement

Type of funding sources: None.

The right ventricle: pairing structural with functional assessment

Background

Right Ventricular (RV) dysfunction is a well-recognized prognostic marker in the natural history of left-sided Heart Failure (HF). Common experience dictates that structural and functional evaluation are often seemingly discrepant. We aimed to evaluate the correlation between RV function by transthoracic echocardiography (TTE) and Right Heart Catheterization (RHC) parameters, and their prognostic value in patients with HF.

Methods

We designed a retrospective single-centre study of patients with advanced HF referred to TTE and RHC as part of Heart Transplant candidacy evaluation, from 2010 to 2019. Pulmonary Hypertension (PH) was defined by a mean pulmonary artery pressure (mPAP) ≥25mmHg. Patients with PH other than Group II (WHO) PH were excluded. In appropriate cases, vasodilator challenge with inhaled NO was performed. The primary endpoint was a composite of death, heart transplant or HF hospitalization at 6 months.

Results

The cohort was comprised of 68 patients (mean age 56±11 years, 73.5% male, ischaemic HF 44.1%). Most patients had PH (n=61) and TTE evidence of RV dysfunction (n=46). The strongest correlations between RHC and TTE parameters were moderate at best – mPAP, pulmonary capillary wedge pressure and central venous pressure with E/A ratio (Pearson r 0,461, 0,533 and 0,543, respectively; p<0.05); and RV stroke work index and mPAP with non-invasive estimated systolic pulmonary artery (PA) pressure (Pearson r 0,483 and 0,481, respectively; p<0.05). Over a median follow-up of 26 (12–42) months, 53 patients had a primary endpoint event, of whom 36 within 6 months. The best model integrating data from structural and functional assessment to predict the primary endpoint included the systolic PA pressure to stroke volume ratio – i.e. PA elastance (HR per 0.10 units: 2.817; 95% CI 1.030–1.338; p=0.016) – and RV free wall longitudinal strain (HR per −1%: 0.792; 95% CI 0.656–0.956; p=0.015). ROC curve analysis disclosed the best cut-off values as follows: 1.3 (sensitivity 77.2%, specificity 65.6%) and −18% (sensitivity 10.7%, specificity 86.4%), respectively.

Conclusion

In a cohort of patients with advanced HF, who were potential candidates for heart transplantation, RV dysfunction was often noted. The model with highest accuracy to predict the primary outcome integrated RV structural with functional data. Additional studies are warranted to define well-validated scores useful in the algorithmic therapeutic decision of advanced HF.

Funding Acknowledgement

Type of funding sources: None.

Regurgitant volume to left ventricular end-diastolic volume ratio: the quest to identify Disproportionate MR is not over

Background

Quantification of secondary mitral valve regurgitation (SMR) remains challenging. Proportionate and Disproportionate SMR provides a conceptual framework that relates the degree of SMR to left ventricular dilatation and dysfunction. In line with this concept, regurgitant volume to LV end-diastolic volume ratio (Rvol/LVEDV) was recently proposed as a possible strategy to identify patients with Disproportionate SMR. The aim of this study was to validate this approach in a Portuguese cohort.

Methods

In a single center cohort of patients with heart failure and reduced left ventricular ejection fraction (HFrEF <50%) under optimal guideline-directed medical therapy (GDMT), we retrospectively identified those with at least moderate SMR. According to the published literature, we divided the study population into 2 risk groups: those with a Rvol/LVEDV ratio ≥20% (greater MR/smaller LVEDV) and those with a ratio <20% (smaller MR/ larger EDV). Cox regression and Kaplan-Meier survival analysis were used to assess the association between Rvol/LVEDV ratio and all-cause mortality.

Results

A total of 154 patients (mean age 69±12 years; 81% male) were included. Mean LVEF was 31±8% and median LVEDV was 193 mL (IQR: 155 to 236 mL). There were 74 patients (48.1%) with a Rvol/LVEDV ratio <20% and 80 patients (51.9%) Rvol/LVEDV ratio ≥20%. Regarding GDMT, 141 (91.6%) received beta-blockers, 139 (90.3%) angiotensin converting–enzyme inhibitors/angiotensin receptor blockers and 77 (50.0%) were under mineralocorticoid therapy. Also, there were patients 49 (31.8%) under cardiac resynchronization therapy and 40 patients (26.0%) had an implantable cardioverter defibrillator. During a median follow-up of 2.1 years (IQR 0.7 to 3.8 years), 92 (59.7%) patients died. Cox regression and survival analysis showed no mortality difference between patients with a Rvol/LVEDV ratio <20% and those with a ratio ≥20% (HR: 1.04; 95% CI 0.69–1.57; P=0.854; Log-rank P=0.967) – see also figure.

Conclusion

In a Portuguese cohort of HFrEF patients under optimized GDMT and with at least moderate SMR, the Rvol/LVEDV ratio was not associated with an increased risk of all-cause mortality. As such, the Rvol/LVEDV ratio does not seem to be a reliable surrogate of Disproportionate SMR, possibly because it does not account for the degree of LV dysfunction.

Funding Acknowledgement

Type of funding sources: None.

A new electrophysiological triad for atrial flutter critical isthmus identification and localization

Introduction

In a previous retrospective study it was demonstrated that an electrophysiological triad was able to identify critical isthmus in atrial flutter (AFL) patients. This triad is based in the Carto® electroanatomical mapping (EAM) version 7, which displays a histogram of the local activation times (LAT) of the tachycardia cycle length (TCL), in addition to the activation and voltage maps. This study aimed to prospectively assess the ability of an electrophysiological triad to identify and localize the AFL's critical isthmus.

Methods

Prospective analysis of a unicentric registry of individuals who underwent left AFL ablation with Carto® EAM. All patients with non-left AFL, lack of high-density EAM, less than 2000 collected points or lack of mapping in any of the left atrium walls or structures were excluded. Ablation sites of arrhythmia termination were compared to an electrophysiological triad constituted by: areas of low-voltage (0.05 to 0.3mV), sites of deep histogram valleys (LAT-Valleys) with less than 20% density points relative to the highest density zone and a prolonged LAT-Valley duration that included 10% or more of the TCL. The longest LAT-Valley was designated as the primary valley, while additional valleys were named as secondary.

Results

A total of 12 patients (9 men, median age 72 IQR 67–75 years) were included. All patients presented with left AFL and 67% had a previous atrial fibrillation and/or flutter ablation. The median TCL and number collected points were 250 (230–290) milliseconds and 3150 (IQR 2340–3870) points, respectively. All AFL presented with at least 1 LAT-Valley in the analysed histograms, which corresponded to heterogeneous low-voltage areas (0.05 to 0.3mV) and encompassed more than 10% of TCL. Eleven of the 12 patients presented with at least 1 secondary LAT-Valley. All arrhythmias were effectively terminated after undergoing radiofrequency ablation in the primary or the secondary LAT-Valley location.

Conclusion

In a prospective analysis, an electrophysiological triad was able to identify the AFL critical isthmus in all patients. Further studies are needed to assess the usefulness of this algorithm to improve catheter ablation outcomes.

Funding Acknowledgement

Type of funding sources: None.

Incorporating coronary calcification into pretest assessment of the likelihood of coronary artery disease: validation and recalibration of a new diagnostic tool

Background

A new clinical tool was recently proposed to improve the estimation of pre-test probability of obstructive coronary artery disease (CAD) by incorporating coronary artery calcium score (CACS) with clinical risk factors. This new model (Clinical+CACS) showed improved prediction when compared to the method recommended by the 2019 ESC guidelines on chronic coronary syndromes, but was never tested or adjusted for use in our population. The aim of this study was to assess the performance of this new method in a Portuguese cohort of symptomatic patients referred for coronary computed tomography angiography (CCTA), and to recalibrate it if necessary.

Methods

We conducted a two-center cross-sectional study assessing symptomatic patients who underwent CCTA for suspected CAD. Key exclusion criteria were age <30 years, known CAD, suspected acute coronary syndrome, or symptoms other than chest pain or dyspnea. Obstructive CAD was defined as any luminal stenosis ≥50% on CCTA. The Clinical+CACS prediction model was assessed for discrimination and calibration. A logistical recalibration of the model was conducted in a random sample of 50% of the patients and subsequently validated in the other half.

Results

A total of 1910 patients (mean age 60±11 years, 60% women) were included in the analysis. Symptom characteristics were: 39% non-anginal chest pain, 30% atypical angina, 19% dyspnea and 12% typical angina. The observed prevalence of obstructive CAD was 12.9% (n=247). Patients with obstructive CAD were more often male, were significantly older, had higher prevalence of typical angina and cardiovascular risk factors, and higher CACS values. The new Clinical+CACS tool showed greater discriminative power than the ESC 2019 prediction model, with a C-statistic of 0.83 (CI 95% 0.81–0.86) versus 0.67 (CI 95% 0.64–0.71), respectively (p-value for comparison <0.001). Before recalibration, the Clinical+CACS model underestimated the likelihood of CAD in our population across all quartiles of pretest probability (mean relative underestimation of 49%), which was subsequently corrected by the recalibration procedure - Figure.

Conclusions

In a Portuguese cohort of symptomatic patients undergoing CCTA for suspected CAD, the new Clinical+CACS model showed better discrimination power than the 2019 ESC method. The underestimation of the Clinical+CACS model was corrected by recalibrating it for our population. This new tool might prove useful for guiding decisions on the need for further testing.

Funding Acknowledgement

Type of funding sources: None.

Electrical anatomy of the left atrium during atrial fibrillation

Introduction

Twenty years ago, pulmonary veins (PV) ostia were identified as the left atrium (LA) areas with the shortest refractory period during sinus rhythm. Pulmonary veins isolation (PVI) became standard of care, but clinical results are still suboptimal. Today, a special tool using the Carto® electroanatomical mapping (EAM) allows for AF cycle length mapping (CLM), to identify the areas in the left atria with shortest refractory period, during atrial fibrillation. Using this EAM tool, our study aimed to find the LA areas with the shortest refractory period to better recognize electrical targets for catheter ablation.

Methods

Retrospective analysis of an unicentric registry of individuals with symptomatic drug-refractory AF who underwent PVI with Carto® EAM. CLM was performed with a high-density mapping Pentaray® catheter before and after PVI and in 4 redo procedures. We assessed areas of short cycle length (SCL) (defined as 120 to 250ms), and their relationships with complex fractionated atrial electrograms (CFAE), and low-voltage zones (from 0.1 to 0.3mV).

Results

A total of 18 patients (8 men, median age 63 IQR 58–71 years) were included. Most patients presented with persistent AF (n=12, 67%), and 4 patients (22%) had a previous PVI. The mean shortest measured cycle length in AF was 140ms (SD ±27ms). All patients presented areas of SCL located in the PVs or their insertion, 70% in the posterior/roof region adjacent to the left superior pulmonary vein (LSPV) (figure 1) and 60% in the anterior region of the right superior pulmonary vein (RSPV). These two areas remained the fastest even after PVI. The anterior mitral region rarely presented SCL (17%). SCL were related to low-voltage areas in 94% and were adjacent to CFAE. Low-voltage areas and CFAE were more frequent and had a larger LA dispersion than SCL.

Conclusion

We confirmed in 3D mapping that PVs are the LA zones with shortest refractory period, not only in sinus rhythm but also during AF. The persistence of SCL areas in the border zones of the PVI lines suggest the benefit of a more extensive CLM guided ablation. Larger studies are needed.

Funding Acknowledgement

Type of funding sources: None. Short cycle length mapping

Impact of COVID-19 pandemic on ST-elevation myocardial infarction: data from two Portuguese centers

Introduction

Recently during the COVID-19 pandemic there was a general belief in a reduction of hospital admissions due to non-infectious causes, namely cardiovascular diseases.

Objectives

To evaluate the impact of the pandemic in the admissions by ST elevation acute myocardial infarction (STEMI), during the first pandemic wave.

Methods

Multicentric and retrospective analysis of consecutive patients presenting in two Portuguese hospital centers with STEMI in two sequential periods – P1 (1st March to 30th April) and P2 (1st May to 30th June). A comparison of patient's clinical and hospital outcomes data was performed between the year 2020 and 2017 to 2019 for both periods.

Results

A total of 347 consecutive STEMI patients were included in this study. The patient's baseline characteristics and cardiovascular risk factors were similar across the considered periods. During P1 of 2020, in comparison with previous years, a reduction in the number of STEMI patients was observed (26.0±4.2 vs 16.5±4.9 cases per month; p=0.033), contrary to what was observed during P2 (19.5±0.7 vs 20.5±0.7 cases per month; p=0.500). Percutaneous coronary interventions in the setting of failed thrombolysis were more frequent (1.9% vs 9.1%; p=0.033). A global trend in longer delays in time-key bundles of STEMI care was noted, namely pain to first medical contact, door to needle, door to wire crossing and symptoms to wire crossing times, however without statistical significance. Mortality rate was six-fold higher during P1 comparing to previous years (1.9% vs 12.1%; p=0.005), and also an increase in the number of mechanical complications (0.0% vs 3.0%; p=0.029) was observed.

Conclusions

During the first COVID-19 pandemic wave there were fewer patients presenting with STEMI at catheterization laboratory for coronary angioplasty. These patients presented more mechanical complications and higher mortality rates.

Funding Acknowledgement

Type of funding sources: None.

The gray zone of myocardial fibrosis is a better predictor of ventricular arrhythmias than total myocardial fibrosis in patients with previous myocardial infarction

Background

Current sudden cardiac death (SCD) risk stratification relies heavily on the assessment of left ventricular ejection fraction (LVEF), but markers that could refine risk assessment are needed. Total fibrosis mass (TFM) and “gray zone” of myocardial fibrosis (GZF) on late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) have been proposed as potential arrhythmogenic substrates. The aim of our study was to determine whether TFM and GZF can predict the occurrence of ventricular arrhythmias in patients with previous myocardial infarction.

Methods

We performed a single centre retrospective study enrolling all consecutive patients with previous myocardial infarction undergoing LGE-CMR before implantable cardioverter-defibrillator (ICD) implantation for primary or secondary prevention. TFM and GZF were defined as myocardial tissue with signal-intensities >6 SD and 2–6 SD above the mean of reference myocardium, respectively. The primary endpoint was a composite of sudden arrhythmic death, appropriate ICD shock, ventricular fibrillation (VF), or sustained ventricular tachycardia (VT) as detected by the device.

Results

A total of 55 patients (mean age 62±12 years, 87% male, mean LVEF 30% ± 8%) were included. During a mean follow-up period of 34±15 months, 10 patients reached the primary endpoint (8 appropriate ICD shock, 2 sustained VT or VF). Patients who attained the primary endpoint had similar TFM (28.6g ± 14.5 vs. 23.1g ± 14.5; P=0.283) but larger GZF (25.3g ± 11.0 vs 15.6g ± 7.3; P=0.001). After adjustment for LVEF, GZF remained independently associated with the composite arrhythmic endpoint (adjusted hazard ratio [aHR]: 1.10; 95% CI: 1.03–1.17; P=0.005), whereas TFM did not (aHR: 1.02; 95% CI: 0.98–1.06; P=0.394). Decision tree analysis identified 16.4g of GZF as the best cut-off to predict life-threatening arrhythmic events. The primary endpoint occurred in 9 out of the 22 patients (41%) with GZF >16.4g, but in only 1 of the 33 patients (3%) with GZF ≤16.4g – Figure.

Conclusions

The extent of GZF seems to be a better predictor of ventricular arrhythmias than TFM. This LGE-CMR parameter may be useful to identify a subgroup of patients with previous myocardial infarction at an increased risk of life-threatening arrhythmic events.

Funding Acknowledgement

Type of funding sources: None.

The odyssey to dethrone LV ejection fraction continues: the prognostic value of LV global function index in heart failure

Background

Left Ventricular (LV) Global Function index (LVGFi) is a parameter that combines data from global systolic performance and volumetric anatomical information, measurable by non-contrast Cardiac Magnetic Resonance (CMR). We aimed to evaluate whether LVGFi predicts major cardiovascular outcomes and outperforms LV ejection fraction (LVEF) in Heart Failure (HF).

Methods

We conducted a retrospective single-centre study of consecutive patients with HF who were referred to and had a LVEF <50% at CMR. Other than inadequate images for endocardial or epicardial border delineation, there were no exclusion criteria. LVEF was determined by 3D measurement. LVGFi was calculated as the LV stroke volume to the LV global volume ratio (Figure 1). The primary endpoint was a composite of time to all-cause death or HF hospitalization.

Results

The cohort was comprised of 433 HF patients (mean age 64±12 years, 74.1% male, ischaemic HF 53.1%, NYHA I-II 83.9%) with a mean LVEF of 33.5±10.0% and LVGFi of 22.8±7.4%. Over a median follow-up of 27 (17–37) months, 85 (19.6%) met the primary endpoint and 42 (9.7%) died. Patients with an event of the primary endpoint had markers of more severe HF, as noted by a reduced functional capacity (NYHA I-II: 63.5 vs. 89.0%; p<0.001) and increased natriuretic peptides [NT-proBNP: 2664 (1022–27242) vs. 791 (337–7258); p<0.001). Likewise, CMR showed higher LV volumes (e.g., LV end-diastolic volume index: 137±50 vs. 120±43mL/m2; p=0.001) and reduced LV performance indices, namely LVEF (29.2±10.6 vs 34.5±9.6%; p<0.001) and LVGFi (19.8±7.4 vs 23.6±7.3%; p<0.001). Both LVEF and LVGFi independently predicted the primary endpoint in multivariate analysis (separately imputed into a model adjusted for NYHA, NT-proBNP and creatinine). The LVEF model was more powerful than that of LVGFi. Similarly, LVGFi did not provide incremental prognostic information over LVEF in c-statistics analysis (0.653 vs. 0.622; p=0.645) (Figure 2).

Conclusion

While LVGFi independently predicted major outcomes in patients with HF and LVEF <50%, it did not surpass LVEF. Our findings contrast to those demonstrating LVGFi as a powerful variable that outperforms LVEF in hypertrophic cardiomyopathy, cardiac amyloidosis, and healthy subjects at risk of developing structural heart disease. We hypothesize that LVGFi might be primarily useful in the prognostic stratification of patients with preserved LVEF.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Coronary artery calcium score to predict coronary CT angiography interpretability. An old problem revisited

Introduction

Clinical guidelines recommend against the use of coronary computed tomography angiography (CCTA) in patients with heavy calcification due to interpretability concerns, but no specific approach or threshold is provided. Recently, alternative methods have been proposed as more reliable predictors of CCTA interpretability than the classic coronary artery calcium score (CACS). The purpose this study was to compare the performance of different measures of coronary calcification as predictors of CCTA interpretability.

Methods

We conducted a retrospective analysis of consecutive patients undergoing CACS and CCTA between 2018 and 2020. The key exclusion criteria were known coronary artery disease, CACS of zero, and presence of non-assessable coronary lesions for reasons other than calcification (movement/gating artifacts or vessel diameter <2mm). CCTA studies were considered non-interpretable if the main reader considered one or more coronary lesions non-assessable due to calcification. Three different measures of coronary calcification were compared using ROC curve analysis: 1) total CACS; 2) CACS-to-lesion ratio (total CACS divided by the number of calcified plaques); and 3) calcium score of the most calcified plaque. Decision-tree analysis was performed to identify the algorithm that best predicts CCTA interpretability.

Results

A total of 432 patients (191 women, mean age 64±11 years) were included. Overall, 31 patients (7.2%) had a non-interpretable CCTA due to calcification. Patients with non-interpretable CCTA had higher CACS (median 589 vs. 50 AU, p<0.001), higher CACS-to-lesion ratio (median 43 vs. 14 AU/lesion, p<0.001), and higher score of the most calcified plaque (median 445 vs. 43 AU, p<0.001). Among the 3 methods, CACS showed the highest discriminative power to predict a non-interpretable CCTA (C-statistic 0.93, 95% CI 0.89–0.95, p<0.001) – Figure 1.

Decision-tree analysis identified a single-variable algorithm (CACS value ≤515 AU) as the best discriminator of CCTA interpretability: 396 of the 409 patients (97%) with CACS ≤515 AU had an interpretable CCTA, whereas only 5 of the 23 patients (22%) with CACS >515 AU had an interpretable test, yielding a total of 96% correct predictions.

Conclusions

The recently proposed and more complex measures of coronary calcification seem unable to outperform total CACS as a predictor of CCTA interpretability. A simple CACS cutoff-value around 500 AU remains the best discriminator for this purpose.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Anticipating recurrent ischemic events after an acute coronary syndrome: validation and application of the SMART-REACH score

Background

The SMART-REACH score (SRS) was developed to predict the risk of major adverse cardiovascular events in ambulatory patients with established cardiovascular disease, although it has not been extensively validated. Patients at higher risk of recurrent ischemic events may benefit from novel, more intensive treatment options, and earlier identification of these patients can potentially improve outcomes.

Purpose

We aimed to validate the SRS and evaluate its performance in a population recently admitted with acute coronary syndrome.

Methods

In this single-centre retrospective cohort, we included 320 patients aged 45 to 80 years, who were discharged following admission for an acute coronary syndrome between 2016 and 2018. To calculate the SRS for each patient, we considered clinical data on admission (age, gender, smoking, diabetes, prior history of vascular disease, heart failure or atrial fibrillation), lipid values obtained within the first 24 hours of hospitalization, serum creatinine level at baseline and once the patient was deemed clinically stable, and discharge medication. The outcome of interest was defined as stroke, myocardial infarction or cardiovascular death (MACE) at two years of follow-up. SRS was assessed for discrimination and calibration.

Results

Mean age was 63±9 years, and 240 (75%) were male. There was high prevalence of cardiovascular risk factors: 71% had hypertension, 32% had diabetes mellitus, 42% were active smokers and 25% had previously established cardiovascular disease. The outcome of interest was observed in 38 patients (22 cardiovascular deaths, 6 strokes and 14 myocardial infarctions). SRS showed good discrimination of the estimated MACE risk with overall C-statistic of 0.646 (95% CI, 0.554–0.737, p=0.004) (picture 1) and calibration (p-value for the goodness-of-fit test of 0.544). The global estimated risk of MACE at 2-years was 4.8% (3.8%-6.8%). The expected/ observed ratio was 0.56 for the occurrence MACE (picture 2).

Conclusions

Over the first two years after discharge from an acute coronary syndrome, one of every 8 patients developed a potentially fatal recurrent ischemic event. The SRS performed reasonably well in discriminating those at highest risk of MACE, suggesting that this score may help select patients at discharge for ad initium more intensive pharmacological therapy.

Funding Acknowledgement

Type of funding sources: None. ROC curve for the SMART-REACH scoreExpected versus observed MACE

Prevalence and determinants of right ventricular dysfunction in patients with severe symptomatic high gradient aortic stenosis

Background

Right ventricular (RV) function in aortic stenosis (AS) has been largely neglected. Recently it was demonstrated that right ventricular impairment may be influenced by left ventricular (LV) function and afterload, well before overt pulmonary hypertension development.

Aim

To describe the prevalence of RV dysfunction in a group of patients with severe symptomatic aortic stenosis (AS) and its relation to LV function parameters and afterload.

Methods

We prospectively studied 93 consecutive patients (age: 73 years [IQR 68–77] years, 55% women) with pure severe symptomatic high gradient aortic stenosis: mean transaortic pressure gradient: 57.0mmHg [IQR 46.9–71.1]; aortic valve area: 0.72cm2 [IQR 0.61–0.88]; indexed stroke volume: 48.8±1.5 mL/m2 (11 patients with low-flow AS), preserved LV ejection fraction (EV) (LVEF: 56.0% [51.0–61.3]; GLS: −14.5% [IQR −16.1 to −10.6]), with no previous coronary artery disease and no history of cardiomyopathy. Beyond complete transthoracic echocardiography, all patients underwent cardiac magnetic resonance (CMR) for LV myocardium tissue characterization (late gadolinium enhancement and extracellular volume). Normal RV function was defined according to TAPSE ≥17mm, tricuspid annular systolic velocity ≥12cm/s, mean free wall longitudinal strain ≤−20%. Patients were divided into four groups: (0) – all three RV parameters below normal (1.1%), (1) – 1 normal parameter (12.9%), (2) – 2 normal parameters (44.1%), (3) – 3 normal parameters (41.9%). Indexes of LV systolic and diastolic function, CMR derived LV geometric remodeling, hypertrophy and tissue characterization, aortic valve disease severity and afterload were compared across the 4 groups of patients. We tried to identify predictors of RV dysfunction (group 0, 1, 2 vs. group 3) at multivariate regression analysis.

Results

Left ventricular performance parameters, diastolic and myocardial work indexes were significantly different across the groups (Figure). Neither AV severity indexes nor LV tissue characterization were distinct. At multivariate analysis only global constructive work was an independent predictor of RV dysfunction.

Conclusion

RV dysfunction is common in this group of patients with severe high gradient aortic stenosis and preserved ejection fraction. RV impairment is significantly related to several LV systolic and diastolic parameters and also to LV afterload, probably accounting for RV-LV interdependence.

Funding Acknowledgement

Type of funding sources: None.

Chronic heart failure in intensive care unit: can we accurately predict the risk?

Background

Severity of disease scoring systems, namely the Simplified Acute Physiology Score (SAPS) and Acute Physiology and Chronic Health Evaluation (APACHE), are widely used to predict mortality in Intensive Care Units (ICU). Yet, neither score includes chronic HF in their model. We aimed to evaluate whether these scores perform well in risk prediction of death of patients previously diagnosed with heart failure (HF).

Methodology

This is a single-center retrospective cohort of patients admitted to an ICU in 2019. Those whose admission lasted <24 hours were excluded from analysis. The SAPS II and APACHE II scores were calculated using data from the first 24 hours of ICU admission, imputing the worst variable obtained within this timeframe. HF was defined according to the ESC recommendations. In order to assess the performance of the scores, Receiver Operating Characteristic (ROC) Curves were used to predict the risk of death in ICU in HF compared to the non-HF population.

Results

A total of 267 patients were hospitalized in ICU for a period over 24 hours in 2019 (mean age 67±16 years; 58.8% males; 21.7% with chronic HF; 33.7% admitted for sepsis). Compared to patients without HF, those with chronic HF were older (74±13 vs. 65±16 years; p<0.001) and had higher risk scores (mean SAPS II: 43.2±21.7 vs. 56.5±20.7; p<0.001; mean APACHE II: 19.8±10.0 vs. 25.1±10.0; p<0.001). Moreover, these patients were at higher risk of meaningful events during hospitalization (e.g. acute kidney injury: 38.0 vs. 66.1%; p<0.001; shock at any time: 52.4 vs. 67.8%; p=0.036). Furthermore, patients with HF had a trend towards higher mortality rates in ICU (17.3 vs. 28.8%; p=0.051) and a significantly higher death in overall hospitalization (30.8 vs. 45.8%; p=0.032). ROC curves performed well in predicting the risk of ICU death regardless of HF (SAPS II – AUC 0.78 vs. 0.81; p=0.36; APACHE II – AUC 0.75 vs. 0.78; p=0.37).

Conclusion

Approximately 1 in every 4 patients admitted to the ICU had chronic HF. Traditional risk scoring systems (SAPS II and APACHE II) performed well regardless of HF. While these results are reassuring as far as risk stratification accuracy is concerned, HF patients remained at a higher risk for worse outcomes. Therefore, prognostic tools with a therapeutic clinical applicability are urgently needed to improve the outcome of this population.

Funding Acknowledgement

Type of funding sources: None.

Long-term durability of transcatheter aortic valve replacement: outcomes from a contemporary cohort from a tertiary reference center at 5-years and beyond

Background and aim

Long-term data on the durability of transcatheter heart valves is scarce. This is of particular interest as indications expand to younger and lower surgical risk patients. We sought to assess the incidence of long-term structural valve dysfunction (SVD) and bioprosthetic valve failure (BVF) in a cohort of patients with TAVR who reached at least 5-year follow-up, as compared to surgical aortic valve replacement (SAVR), performed within the same time-frame at the same institution.

Methods and results

Consecutive patients with at least 5-year available follow-up, who underwent TAVR between November 2008 to December 2015 in a tertiary single center, were included. From a group of 246 patients undergoing TAVR, 126 had available follow-up data (age at implantation: 83.0 [77.8–87.0] years; EuroScore II: 4.54 [2.60–6.29]%; follow-up: 5.94 [5.06–7.67] years). First generation Corevalve® and Sapien® prosthesis were implanted in 56% and 38% patients, respectively.

SVD and BVF were defined according to the new consensus statement from the EAPCI endorsed by the ESC and the EACTS. Mean transaortic pressure gradients decreased from 53.2±1.3 mmHg (pre-TAVR) to 10.4±0.4 mmHg (at discharge or up to one-year after TAVR, p<0.001), and there was a small non-significant increase at the fifth-year and the last available follow-up (11.2±0.6 mmHg; 14.7±1.8 mmHg, respectively). Moderate and severe SVD were reported in 12 and 4 patients, respectively (8-year cumulative incidence function to SVD: 2.67%; 95% CI, 2.12–3.89). Of these 8 had BVF, 7 of them with hospitalization for acute heart failure. A total of 4 patients died and none required reintervention (redo TAVR or SAVR). BVF for non-SVD were observed in 4 patients (2 subclinic thrombosis successfully treated with anticoagulation and 2 paravalvular regurgitation due to endocarditis).

As comparator, from a cohort of 587 patients submitted to biological SAVR, 247 (age 75.0 [70.0–79.0] years; EuroScore II 1.43 [1.06–2.17]%) had available long-term follow-up (6.89 [6.08–8.19] years). Moderate and severe SVD were reported in 42 and 3 patients, respectively (8-year cumulative incidence function to SVD: 3.13%; 95% CI, 2.45–4.21). These events were clinically relevant (BVF) in 19 of them: 8 performed TAVR valve-in-valve procedures and 3 redo SAVR. At the fifth-year of follow-up the incidence of SVD was not statistically different between TAVR (8%) and SAVR (15%), with a p for comparison of 0.137.

Conclusions

In our population of patients with symptomatic severe aortic stenosis treated with first-generation percutaneous bioprostheses, TAVR was associated with a low incidence of BVF and SVD at the long-term follow-up. These outcomes seem indistinct from those occurring in patients submitted to conventional SAVR

Funding Acknowledgement

Type of funding sources: None. KM curve reporting probability of SVD

Prognostic impact of the presence and management of coronary artery disease in patients undergoing TAVI

Introduction

Approximately half of transcatheter aortic valve implantaton (TAVI) candidates have coronary artery disease (CAD). Controversial results have been reported regarding the effect of the presence/severity of CAD and its management on clinical outcomes post-TAVI.

Aim

To describe the presence, extension, severityand management of CAD pre-TAVIand to evaluate its impact on 2-yearmortality in areal world all comers population.

Methods and population

Single centre retrospective analysis from a prospectively collected institutional registry (VCROSS) including 517 patients that underwent TAVI for severe aortic stenosis between January 2009 and December 2018. Patients who underwent pre TAVI CA in the context of ACS or at other institution were excluded n=138. Ultimately 380 entered the analysis. Obstructive CAD was defined as stenosis >50% in in major epicardial vessels (>2.5 mm). The total number of major epicardial with obstructive CAD was reported as was assessed the number of those left untreated. Univariate analysis was performed to assess 1) differences between patients with or without CAD and between those with significant CAD who have or have not undergone PCI, 2) variables associated with 2-year mortality. Binary logistic regression was performed to identify independent predictors of 2-year mortality including the presence of significant CAD and the type of management.

Results

A total of 380 patients were included, 55.3% male with an average age of 83YO (±6.3), mean Euroscore II of 4.35. 76 had previous coronary artery bypassgrafting (CABG) and 136 had previous PCI (43 had both). 55 patients (14.4%) presented with normal coronary arteries, 120 (31.6%) with non-obstructive CAD and 205 (54%) with obstructive CAD. Out of the latter, 112 (29.5%) underwent PCI. Statistically significant differences were found between obstructive CAD vs non-obstructive patients in terms of age, previous history of ICP and CABG. In the subgroup population with obstructive CAD, no statistically significant differences was found in the PCI vs non PCI group, apart from previous history of ICP and CABG – Figure 1. Diabetes mellitus, previous history of percutaneous coronary intervention (PCI) and reduced ejection fraction (rEF – defined has <50% echocardiographically) had a negative prognosticimpact in the 2 year mortality of the 380 patients. 2-year mortality was 14,5% (55 patients).The presence and management of CAD pre TAVI had no impact in 2-year mortality, when accounting for the differences in previous ICP history, CABG, age, and rEF.

Conclusion

The presence and type of management of obstructive CAD in this real world all comers registry did not impact the prognosis at 2 years.

Funding Acknowledgement

Type of funding sources: None.

Coronary artery calcium score to predict coronary CT angiography interpretability: an old problem revisited

Funding Acknowledgements

Type of funding sources: None.

Introduction

Clinical guidelines recommend against the use of coronary computed tomography angiography (CCTA) in patients with heavy calcification due to interpretability concerns, but no specific approach or threshold is provided. Recently, alternative methods have been proposed as more reliable predictors of CCTA interpretability than the classic coronary artery calcium score (CACS).  The purpose this study was to compare the performance of different measures of coronary calcification as predictors of CCTA interpretability.

Methods

We conducted a retrospective analysis of consecutive patients undergoing CACS and CCTA between 2018 and 2020. The key exclusion criteria were known coronary artery disease, CACS of zero, and presence of non-assessable coronary lesions for reasons other than calcification (movement/gating artifacts or vessel diameter < 2mm). CCTA studies were considered non-interpretable if the main reader considered one or more coronary lesions non-assessable due to calcification. Three different measures of coronary calcification were compared using ROC curve analysis: 1) total CACS; 2) CACS-to-lesion ratio (total CACS divided by the number of calcified plaques); and 3) calcium score of the most calcified plaque. Decision-tree analysis was performed to identify the algorithm that best predicts CCTA interpretability.

Results

A total of 432 patients (191 women, mean age 64 ± 11 years) were included. Overall, 31 patients (7.2%) had a non-interpretable CCTA due to calcification. Patients with non-interpretable CCTA had higher CACS (median 589 vs. 50 AU, p < 0.001), higher CACS-to-lesion ratio (median 43 vs. 14 AU/lesion, p < 0.001), and higher score of the most calcified plaque (median 445 vs. 43 AU, p < 0.001). Among the 3 methods, CACS showed the highest discriminative power to predict a non-interpretable CCTA (C-statistic 0.93, 95%CI 0.89-0.95, p < 0.001) - Figure.

Decision-tree analysis identified a single-variable algorithm (CACS value ≤ 515 AU) as the best discriminator of CCTA interpretability: 396 of the 409 patients (97%) with CACS ≤ 515 AU had an interpretable CCTA, whereas only 5 of the 23 patients (22%) with CACS > 515 AU had an interpretable test, yielding a total of 96% correct predictions.

Conclusions

The recently proposed and more complex measures of coronary calcification seem unable to outperform total CACS as a predictor of CCTA interpretability. A simple CACS cutoff-value around 500 AU remains the best discriminator for this purpose.

Incorporating coronary calcification into pretest assessment of the likelihood of coronary artery disease: validation and recalibration of a new diagnostic tool

Funding Acknowledgements

Type of funding sources: None.

Background

A new clinical tool was recently proposed to improve the estimation of pre-test probability of obstructive coronary artery disease (CAD) by incorporating coronary artery calcium score (CACS) with clinical risk factors. This new model (Clinical + CACS) showed improved prediction when compared to the method recommended by the 2019 ESC guidelines on chronic coronary syndromes, but was never tested or adjusted for use in our population. The aim of this study was to assess the performance of this new method in a Portuguese cohort of symptomatic patients referred for coronary computed tomography angiography (CCTA), and to recalibrate it if necessary.

Methods

We conducted a two-center cross-sectional study assessing symptomatic patients who underwent CCTA for suspected CAD. Key exclusion criteria were age < 30 years, known CAD, suspected acute coronary syndrome, or symptoms other than chest pain or dyspnea. Obstructive CAD was defined as any luminal stenosis ≥50% on CCTA. The Clinical + CACS prediction model was assessed for discrimination and calibration. A logistical recalibration of the model was conducted in a random sample of 50% of the patients and subsequently validated in the other half.

Results

A total of 1910 patients (mean age 60 ± 11 years, 60% women) were included in the analysis. Symptom characteristics were: 39% non-anginal chest pain, 30% atypical angina, 19% dyspnea and 12% typical angina. The observed prevalence of obstructive CAD was 12.9% (n = 247). Patients with obstructive CAD were more often male, were significantly older, had higher prevalence of typical angina and cardiovascular risk factors, and higher CACS values. The new Clinical + CACS tool showed greater discriminative power than the ESC 2019 prediction model, with a C-statistic of 0.83 (CI 95% 0.81-0.86) versus 0.67 (CI 95% 0.64-0.71), respectively (p-value for comparison < 0.001). Before recalibration, the Clinical + CACS model underestimated the likelihood of CAD in our population across all quartiles of pretest probability (mean relative underestimation of 49%), which was subsequently corrected by the recalibration procedure - Figure.

Conclusions

In a Portuguese cohort of symptomatic patients undergoing CCTA for suspected CAD, the new Clinical + CACS model showed better discrimination power than the 2019 ESC method. The underestimation of the Clinical + CACS model was corrected by recalibrating it for our population. This new tool might prove useful for guiding decisions on the need for further testing.

Prognostic impact of subcutaneous implantable cardioverter-defibrillator appropriate and inappropriate shocks

Funding Acknowledgements

Type of funding sources: None.

Background

Previous studies have shown an adverse prognosis for patients with transvenous implantable cardioverter-defibrillators (ICD) who receive both appropriate and inappropriate shocks. There is a paucity of data regarding the prognosis of inappropriate shocks in patients with a subcutaneous ICD (S-ICD).

Purpose

To assess and characterize S-ICD appropriate (AS) and inappropriate shocks (IAS) and their impact on mortality.

Methods

Single center observational registry of 162 consecutive patients who underwent S-ICD implantation for primary and secondary prevention between November 2009 and September 2020. Only follow-up data of at least 6 months was analysed to identify predictors of both IAS and AS and their mortality impact.

Results

A total of 144 patients were included in the analysis. Mean age was 42.2 ± 16.6 years and 75% of the patients were male. One hundred and four patients (72.2%) implanted the S-ICD in primary prevention. The most common etiology was ischemic cardiomyopathy (22.9%) followed by hypertrophic cardiomyopathy (18.8%) and dilated idiopathic cardiomyopathy (14.6%). During a mean follow-up of 42.3 ± 29.9 months a total of 48 patients (33.3%) experienced at least one S-ICD shock. Twenty-nine (20.1%) patients received AS due to VT/VF and 31 patients (21.5%) received IAS. Eighteen (58.1%) of the IAS were due to oversensing/noise/discrimination errors and the remaining due to supraventricular tachycardia. Overall, patients with AS (HR 4.93, 95% CI 1.58-15.36, p = 0.006) and higher number of total AS (HR 1.10, 95% CI 1.00-1.20, p = 0.044) were associated with higher mortality during follow-up. S-ICD IAS therapy did not affect overall mortality (HR 1.71, 95% CI 0.21-14.0, p = 0.616). Conclusions: In patients with S-ICD, those who receive AS, in contrast to IAS, seem to have a worse prognosis. Large scale studies are needed to confirm this hypothesis and to explain this findings. Abstract Figure. Survival curves for AS and IAS

Electrical anatomy of the left atrium during atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Introduction

Twenty years ago, pulmonary veins (PV) ostia were identified as the left atrium (LA) areas with the shortest refractory period during sinus rhythm. Pulmonary veins isolation (PVI) became standard of care, but clinical results are still suboptimal. Today, a special tool using the Carto® electroanatomical mapping (EAM) allows for AF cycle length mapping (CLM), to identify the areas in the left atria with shortest refractory period, during atrial fibrillation. Using this EAM tool, our study aimed to find the LA areas with the shortest refractory period to better recognize electrical targets for catheter ablation.

Methods

Retrospective analysis of an unicentric registry of individuals with symptomatic drug-refractory AF who underwent PVI with Carto® EAM. CLM was performed with a high-density mapping Pentaray® catheter before and after PVI and in 4 redo procedures. We assessed areas of short cycle length (SCL) (defined as 120 to 250ms), and their relationships with complex fractionated atrial electrograms (CFAE), and low-voltage zones (from 0.1 to 0.3mV).

Results

A total of 18 patients (8 men, median age 63 IQR 58-71 years) were included. Most patients presented with persistent AF (n = 12, 67%), and 4 patients (22%) had a previous PVI. The mean shortest measured cycle length in AF was 140ms (SD ±27ms). All patients presented areas of SCL located in the PVs or their insertion, 70% in the posterior/roof region adjacent to the left superior pulmonary vein (LSPV) (figure 1) and 60% in the anterior region of the right superior pulmonary vein (RSPV). These two areas remained the fastest even after PVI. The anterior mitral region rarely presented SCL (17%). SCL were related to low-voltage areas in 94% and were adjacent to CFAE. Low-voltage areas and CFAE were more frequent and had a larger LA dispersion than SCL.

Conclusion

  We confirmed in 3D mapping that PVs are the LA zones with shortest refractory period, not only in sinus rhythm but also during AF. The persistence of SCL areas in the border zones of the PVI lines suggest the benefit of a more extensive CLM guided ablation. Larger studies are needed. Abstract Figure 1

Ventricular tachycardia ablation in nonischemic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

INTRODUCTION

Catheter ablation outcomes for drug-resistant ventricular tachycardia (VT) in nonischemic cardiomyopathy (NICM) are suboptimal when compared to ischemic cardiomyopathy. We aimed to analyse the long-term efficacy and safety of percutaneous catheter ablation in this subset of patients.

METHODS

Single-center observational retrospective registry including consecutive NICM patients who underwent catheter ablation for drug-resistant VT during a 10-year period. The efficacy endpoint was defined as VT-free survival after catheter ablation, while safety outcomes were defined by 30-days mortality and procedure-related complications. Independent predictors of VT recurrence were assessed by Cox regression.

RESULTS

In a population of 68 patients, most were male (85%), mean left ventricular ejection fraction (LVEF) was 34 ± 12%, and mean age was 58 ± 15 years. All patients had an implantable cardioverter-defibrillator. Twenty-six (38%) patients underwent epicardial ablation (table 1). Over a median follow-up of 3 years (IQR 1-8), 41% (n = 31) patients had VT recurrence and 28% died (n = 19). Multivariate survival analysis identified LVEF (HR= 0.98; 95%CI 0.92-0.99, p = 0.046) and VT storm at presentation (HR = 2.38; 95%CI 1.04-5.46, p = 0.041) as independent predictors of VT recurrence. The yearly rates of VT recurrence and overall mortality were 21%/year and 10%/year, respectively. No patients died at 30-days post-procedure, and mean hospital length of stay was 5 ± 6 days. The complication rate was 7% (n = 5, table 1), mostly in patients undergoing epicardial ablation (4 vs 1 in endocardial ablation, P = 0.046).

CONCLUSION

LVEF and VT storm at presentation were independent predictors of VT recurrence in NICM patients after catheter ablation. While clinical outcomes can be improved with further technical and scientific development, a tailored endocardial/epicardial approach was safe, with low overall number of complications and no 30-days mortality. Abstract Figure.