Functional Assessment of Coronary Artery Disease in Patients Undergoing Transcatheter Aortic Valve Implantation

Background—

Aortic valve stenosis may influence fractional flow reserve (FFR) of concomitant coronary artery disease by causing hypertrophy and reducing the vasodilatory reserve of the coronary circulation. We sought to investigate whether FFR values might change after valve replacement.

Methods and Results—

The functional relevance of 133 coronary lesions was assessed by FFR in 54 patients with severe aortic valve stenosis before and after transcatheter aortic valve implantation (TAVI) during the same procedure. A linear mixed model was used to verify the interaction of TAVI effect with the FFR values. No significant overall change in FFR values was found before and after the aortic valve stenosis removal (0.89±0.10 versus 0.89±0.13; P =0.73). A different trend in FFR groups (positive if ≤0.8; negative if >0.8) was found after TAVI ( P for interaction <0.001). Positive FFR values worsened after TAVI (0.71±0.11 versus 0.66±0.14). Conversely, negative FFR values improved after TAVI (0.92±0.06 versus 0.93±0.07). Similarly, FFR values in coronary arteries with lesions presenting percent diameter stenosis >50 worsened after TAVI (0.84±0.12 versus 0.82±0.16; P =0.02), whereas FFR values in arteries with mild lesions (percent diameter stenosis <50) tended toward improvement after TAVI (0.90±0.07 versus 0.91±0.09; P =0.69). Functional FFR variations after TAVI changed the indication to treat the coronary stenosis in 8 of 133 (6%) lesions.

Conclusions—

Coronary hemodynamics are influenced by aortic valve stenosis removal. Nevertheless, FFR variations after TAVI are minor and crossed the diagnostic cutoff of 0.8 in a small number of patients after valve replacement. Borderline coronary lesions might become functionally significant after valve replacement, although FFR-guided interventions were infrequent even in patients with angiographically significant lesions.

Clinical outcomes of transcatheter aortic valve implantation: from learning curve to proficiency

Objective

The use of transcatheter aortic valve implantation (TAVI) is growing rapidly in countries with a predominantly elderly population, posing a huge challenge to healthcare systems worldwide. The increment of human and economic resource consumption imposes a careful monitoring of clinical outcomes and cost-benefit balance, and this article is aimed at analysing clinical outcomes related to the TAVI learning curve.

Methods

Outcomes of 177 consecutive transfemoral TAVI procedures performed in 5 years by a single team were analysed by the Cumulative Sum of failures method (CUSUM) according to the clinical events comprised in the Valve Academic Research Consortium (VARC-2) safety end point and the VARC-2 definition of device success. Margins for events acceptance were extrapolated from landmark trials that tested both balloon or self-expandable percutaneous valves.

Results

30-day and 1-year survival rates were 97.2% and 89.9%, respectively. Achievement of the primary end point (number of cases needed to provide the acceptable margin of the composite end point of any death, stroke, myocardial infarction, life-threatening bleeding, major vascular complications, stage 2–3 acute kidney injury and valve-related dysfunction requiring a repeat procedure) required the performance of 54 cases, while the learning curve to achieve ‘device success’ identified 32 cases to reach the expected proficiency. In this experience, the baseline clinical risk as assessed by the Society of Thoracic Surgeons (STS) score determined the long-term survival rather than the adverse events related to the learning curve.

Conclusions

A relatively large number of cases are required to achieve clinical outcomes comparable to those reported in high-volume centres and controlled trials. According to our national workload standards, this represents more than 2 years of continuous activity.

Immediate and long-term clinical performance of bioresorbable vascular scaffolds in a real world population

BACKGROUND

The aim of this study was to evaluate the safety and efficacy of bioresorbable vascular scaffolds (BVS) in terms of acute success and long-term clinical events in a real world population according to the most updated technical recommendations.

METHODS

Perspective, single-center registry involving symptomatic patients treated with BVS from February 2013 to January 2016. Primary end-point was the occurrence of MACCEs at one year: death, target vessel related myocardial infarction, target vessel revascularization, stroke, major bleeding. Secondary endpoints were acute device and procedural clinical success, and occurrence of MACCEs at long-term follow-up.

RESULTS

In total, 112 patients were treated on 173 lesions. Average age was 55.53±12.4 years and acute coronary syndrome was the admission diagnosis for 79.5% patients. Nine patients presented cardiac allograft vasculopathy after cardiac transplantation. Multi-vessel disease was treated in 50% of cases. Predilatation and post-dilatation were performed respectively in 96% and 88.4% of lesions. Intravascular imaging was used in 41 patients (37%). Angiographic success rate and procedural success rate were 100% and 97.3% respectively. Clinical follow-up was completed in 100 patients with an average follow-up of 10.5±8.3 months. Including peri-procedural and in-hospital MACCEs, target vessel failure was noticed in 7% of patients in the first year of follow up and in 11% of patients at long-term follow-up. Two cases of target lesion revascularization occurred 25 and 26 months after the index procedure. No cases of definite stent thrombosis were reported.

CONCLUSIONS

Strict adherence to expert recommendation for BVS placement may minimize device related peri-procedural and mid-to-long term MACCEs in a real world population.

Early and mid-term outcomes of 1904 patients undergoing transcatheter balloon-expandable valve implantation in Italy: results from the Italian Transcatheter Balloon-Expandable Valve Implantation Registry (ITER)

OBJECTIVES

The aim of this multicentre study is to report the clinical experiences of all patients undergoing transcatheter aortic valve implantation (TAVI) with a balloon-expandable device in Italy.

METHODS

The Italian Transcatheter balloon-Expandable valve Registry (ITER) is a real-world registry that includes patients who have undergone TAVI with the Sapien (Edwards Lifesciences, Irvine, CA, USA) bioprosthesis in Italy since it became available in clinical practice. From 2007 to 2012, 1904 patients were enrolled to undergo TAVI in 33 Italian centres. Outcomes were classified according to the updated Valve Academic Research Consortium (VARC-2) definitions. A multivariable analysis was performed to identify independent predictors of all-cause mortality.

RESULTS

Mean age was 81.7 (SD:6.2) years, and 1147 (60.2%) patients were female. Mean Logistic EuroSCORE was 21.1% (SD:13.7). Transfemoral, transapical, transaortic and transaxillary TAVI was performed in 1252 (65.8%), 630 (33.1%), 18 (0.9%) and 4 (0.2%) patients, respectively. Operative mortality was 7.2% (137 patients). The VARC-2 outcomes were as follows: device success, 88.1%; disabling stroke, 1.0%; life-threatening and major bleeding 9.8 and 10.5%, respectively; major vascular complication, 9.7%; acute kidney injury, 8.2%; acute myocardial infarction ≤72 h, 1.5%. Perioperative pacemaker implantation was necessary in 116 (6.1%) patients. At discharge, the mean transprosthetic gradient was 10.7 (SD:4.5) mmHg. Incidence of postoperative mild, moderate or severe paravalvular leak was, respectively, 32.1, 5.0 and 0.4%. A total of 444/1767 (25.1%) deaths after hospital discharge were reported: of these, 168 (37.8%) were classified as cardiac death. Preoperative independent predictors of all-cause mortality were male gender (HR: 1.395; 95% CI:1.052-1.849); overweight, BMI 25-30 kg/m² (HR: 0.775; 95% CI: 0.616-0.974); serum creatinine level (every 1 mg/dl increase; HR: 1.314; 95% CI:1.167-1.480); haemoglobin level (every 1 g/dl increase; HR: 0.905; 95% CI:0.833-0.984); critical preoperative state (HR: 2.282; 95% CI: 1.384-3.761); neurological dysfunction (HR: 1.552; 95% CI:1.060-2.272); atrial fibrillation (HR: 1.556; 95% CI:1.213-1.995); pacemaker rhythm (HR: 1.948; 95% CI:1.310-2.896); NYHA Class III or IV (HR: 1.800; 95% CI:1.205-2.689 or HR: 2.331; 95% CI:1.392-3.903, respectively).

CONCLUSIONS

TAVI with a balloon-expandable device in the 'real world' shows good mid-term outcomes in terms of survival, technical success, valve-related adverse events and haemodynamic performance.

Long-Term (3 Years) Prognosis of Contrast-Induced Acute Kidney Injury After Coronary Angiography

Contrast-induced acute kidney injury (CI-AKI) after coronary angiography or interventions is relatively frequent and portends adverse outcomes. The lack of a "universally accepted" definition, however, limits the integration and comparison of available data. We aimed to detect the CI-AKI definition that best correlates with the occurrence of clinical events at long-term in a 3-year follow-up study of patients at intermediate-to-high risk for CI-AKI. Furthermore, we sought to describe the incidence and long-term evolution of persistent renal damage (PRD) after CI-AKI and clarify the role of early (<12 hours) increments of serum creatinine (SCr) in CI-AKI prediction. Among a total of 216 patients enrolled at our center and followed for a median of 37 months, CI-AKI was diagnosed in 18.1% of cases (SCr increment ≥25% of baseline), 7.4% (SCr increment ≥0.5 mg/dl), and in 17.1% (SCr increment ≥0.3 mg/dl), according to 3 different definitions. The third definition was the only one significantly associated with the occurrence of events at 3 years (Cox regression, p = 0.04). PRD at 30 days, as detected by the same cutoff, significantly and independently identified patients at risk of worst outcomes at 3 years (p = 0.04 at multivariate Cox regression). Furthermore, a slight 5% to 10% increment of SCr compared with baseline, occurring as early as 12 hours postprocedure, was confirmed as a strong predictor of inhospital CI-AKI occurrence. In conclusion, an absolute increase in SCr ≥0.3 mg/dl seems to be most clinically informative cutoff for CI-AKI and PRD detection.

[Position paper on the theoretical basis, practical application and health economic evaluation of the functional assessment of coronary lesions endorsed by the Italian Society of Invasive Cardiology (SICI-GISE)]

Functional assessment of coronary lesions has become an integral part of routine practice in most cath labs. Such evaluation is performed using a pressure wire that allows measurement of fractional flow reserve (FFR). The latter has received a class I indication with level of evidence A according to the most recent European guidelines on myocardial revascularization for the assessment of angiographically moderate coronary lesions. The present document has the following objectives: 1) to summarize the theoretical basis of FFR; 2) to provide a guideline for vasodilator therapy; 3) to summarize scientific evidence supporting FFR; 4) to provide a model of health economy evaluation focusing on resource sparing associated with the use of FFR.

Intracoronary optical coherence tomography: a review of clinical applications

Optical coherence tomography (OCT) is a light-based technology that provides very high spatial resolution images. OCT has been initially employed as a research tool to investigate plaque morphology and stent strut coverage. The introduction of frequency domain OCT allowing fast image acquisition during a prolonged contrast injection via the guiding catheter has made OCT applicable for guidance of coronary interventions. In this manuscript, the various applications of OCT are reviewed, from assessment of plaque vulnerability and severity to characteristics of unstable lesions and thrombus burden to stent optimization and evaluation of late results.

Italian Diffuse/Multivessel Disease ABSORB Prospective Registry (IT-DISAPPEARS). Study design and rationale

BACKGROUND

The Absorb Bioresorbable Vascular Scaffold System (Absorb BVS) is an everolimus-eluting bioresorbable vascular scaffold able to provide temporary scaffolding and antiproliferative drug delivery for the treatment of coronary artery disease. This temporary scaffolding could be the true feature to overcome the limitations of the conventional metallic stents. A growing body of evidence worldwide is supporting its implementation into daily practice as being associated with comparable results as the second-generation everolimus-eluting stent. However, these pieces of evidence come from 'studies in which the majority of the patients had low-risk stenoses', whereas patients with more complex coronary artery disease could benefit the most from the Absorb BVS technology.

METHODS

The aim of the IT-DISAPPEARS is to investigate the procedural and clinical performance of the Absorb BVS in patients with long (>24 mm), single-vessel coronary disease or with multivessel disease. At least 50 centers across the Italian territory will enroll 1000 patients with either stable or acute coronary syndromes. Follow-up will end up at 5 years. Primary endpoint will be the cumulative hierarchical incidence of major adverse cardiac events at 1 year, defined as: cardiac death, nonfatal target vessel myocardial infarction, or clinically driven target lesion revascularization. The efficacy as well as safety parameters will be evaluated along with a detailed evaluation of the dual antiplatelet therapy duration/interruption.

CONCLUSION

The IT-DISAPPEARS could provide the first evidence worldwide concerning the performance of Absorb BVS in patients with high-risk diffuse coronary disease.

Is TAVI superior to surgery in high-risk patients? Insight into the concept of individual risk assessment

The prevalence of aortic valve stenosis (AS) is growing in developed countries because its prevalence increases with age. A growing number of elderly patients are currently referred to specialized centres to be evaluated for potential therapeutic strategies. Indeed, two techniques are nowadays able to treat high-risk AS patients: TAVI and surgical replacement (AVR). It is the purpose of the present review to summarize current knowledge on safety and efficacy of AVR and TAVI in high-risk patients; to focus on some aspects of recently published guidelines; to emphasize the growing importance of pre-operative individual risk assessment, which is considered the real crucial point for patient selection and trial's comparisons. Indeed, it is worth of noting that currently adopted risk-scores do not show satisfactory performances. Accordingly, it becomes of utmost importance to investigate several baseline but still neglected patients' characteristics (e.g. frailty, functional status, co-morbid conditions, etc.), as well as their pathogenetic relationships with interventional results and follow-up prognosis. All these items are emphasized in the present review. Finally, we have tried to anticipate future scenarios in terms of both ongoing clinical trials and improvements of risk-scores.

[Technical features of Absorb(TM) BVS implantation in the IT-DISAPPEARS registry]

Currently, one of the most relevant innovations in interventional cardiology is the advent of bioresorbable vascular scaffolds (BVS). Among the BVS developed so far, the AbsorbTM BVS 1.1 (Abbott®) is one of the two devices that achieved the CE mark for the use in clinical practice. A reasonable amount of clinical evidence on AbsorbTM BVS has been built up from a large series of trials, of which some have been completed and others are in the enrollment and/or follow-up phases. However, at present there is paucity of data on the efficacy and safety of AbsorbTM BVS in patients with more complex coronary artery disease, who represent the majority of those undergoing coronary stenting in everyday clinical practice. To fill this gap, several all-comers registries are ongoing, with the aim to assess the efficacy and safety of the scaffold in subgroups with particularly complex coronary lesions. The AbsorbTM BVS 1.1 registries include IT-DISAPPEARS (NCT02004730), an Italian multicenter registry, started in December 2013, and endorsed by the Italian Society of Invasive Cardiology (GISE). This registry will enroll only patients with long lesions and/or multivessel coronary disease, with an expected considerable proportion of included patients having complex disease. Therefore, the implementation of meticulous and appropriate implantation technique is of key importance for the accurate assessment of scaffold performance in a broad spectrum of coronary lesions. With the aim of standardizing the procedure for patients included in the IT-DISAPPEARS registry, the present article reports the technical features of Absorb TM BVS 1.1 implantation.