Everolimus-eluting bioresorabable scaffold system in the treatment of cardiac allograft vasculopathy: the cardiac allograft reparative therapy (CART) prospective multicentre pilot study

Background

Cardiac allograft vasculopathy (CAV) is still the main drawback of heart transplantation (HTx) and percutaneous coronary intervention (PCI) is a palliative measure because of the high incidence of PCI failure. The bioresorbable scaffolds (BRS) could represent a potential novel therapeutic tool for the treatment of coronary obstructions in CAV.

Purpose

To investigates the effects of BRS implantation in CAV patients in a Nationwide prospective study.

Methods

Multicentre, single-arm, prospective, open-label study that included patients affected by advanced CAV treated with PCI and second-generation ABSORB BRS. The primary endpoint was the incidence of 12-month angiographic in-segment scaffold restenosis (ISSR). Secondary endpoints were the composite of cardiac death, myocardial infarction, and target lesion revascularisation at 12-and 36-month follow-up and the incidence of ISSR at 36 months. A paired analysis of intravascular ultrasound (IVUS) and optical coherence tomography (OCT) at baseline and follow-up was also performed.

Results

Between 2015–2017 35 HTx patients were enrolled and treated on 44 coronary lesions with 51 BRS. The primary endpoint occurred in 13.5% of the lesions (5/37), with a cumulative ISSR rate up to 3 years of 16.2% (6/37).Angiographic lumen loss was 0.40±0.62mm at 12 months and 0.53±0.57mm at 36 months. Overall survival was 91.4% and 74.3%, and MACEs 14.2% and 31.4% at 12 and 36 months, respectively. At the paired intracoronary imaging analysis a significant increase of the vessel external elastic membrane area in the treated segment of the BRS was described at the OCT, while some progression of CAV was detected proximally at the IVUS assessment.

Conclusions

BRS in CAV was feasible and safe, with an ISSR incidence similar to drug-eluting stents. For the first time, a positive remodeling was observed in HTx patients after PCI. Vessel enlargement and the lack of metallic stents may allow repeated PCI avoiding the vessel shrinkage caused by the addition of multiple metal layers, being CAV a complex clinical scenario with a high incidence of MACEs, mainly driven by PCI failure.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Partial funding by Abbott Vascular Italy

Coronary microvascular dysfunction is associated with reduced cardiac performance in low flow low gradient aortic stenosis

Background

Little is known about coronary microvascular function of patients with low-flow low-gradient aortic stenosis (LFLGAS). We hypothesized that LFLGAS is associated with more severe coronary microvascular dysfunction (CMD) compared with normal-flow high-gradient aortic stenosis (NFHGAS) and that CMD is related to reduced cardiac efficiency.

Purpose

To perform a prospective invasive assessment of CMD in patients with LFLGAS undergoing TAVI and to compare it with patients with NFHGAS. Moreover, we aimed to assess the possible acute impact of TAVI on coronary microvascular function and the interactions between CMD and of cardiac performance at speckle tracking echocardiography (STE).

Methods

Invasive thermodilution-based assessment was systematically performed in 41 consecutive patients with isolated severe AS with angiographic unobstructed coronary arteries undergoing TAVI. The index of microcirculatory resistance (IMR), resistive reserve ratio (RRR) and coronary flow reserve (CFR) were derived to assess coronary microcirculatory function before and after TAVI. Advanced echocardiographic imaging, including STE, was performed to assess cardiac function.

Results

IMR was significantly higher in patients with LFLGAS compared with patients with NFHGAS (24.1 [14.6–39.1] vs 12.8 [8.6–19.2] p=0.002). Similarly, RRR was significantly lower in LFLGAS compared with NFHGAS (1.4 [1.1–2.1] vs 2.6 [1.5–3.3] p=0.020). No significant differences were observed in CFR between the two groups.

High IMR was associated with low stroke volume index (rho=−0.427, p=0.005), low cardiac output (rho=−0.517, p=0.001), reduced peak atrial longitudinal strain (PALS) (rho=−0.610, p≤0.001) and presence of atrial fibrillation (54.6% vs 21.1%, p=0.036). Conversely, IMR was only modestly associated with the mean pressure aortic valve gradient (rho=−0.304, p=0.054). Notably, the mean gradient was significantly associated with IMR in the NFHGAS group (rho=0.632, p=0.003) but not in the LFLGAS (rho=−0.222, p=0.333). Similarly, high IMR was associated with the AVA in the NFHGAS group (rho=−0.50, p=0.025) but not in patients with LFLGAS (rho=0.157, p=0.497).

Paradoxical LFLGAS emerged as a phenotype associated with CMD, poor left ventricular longitudinal systolic function and left atrial dysfunction. TAVI determined no significant variation in microvascular function (IMR: 16.0 [10.4–26.1] vs 16.6 [10.2–25.6], p=0.403) and in PALS (15.9 [9.9–26.5] vs 20.1 [12.3–26.7], p=0.222). Conversely, left ventricular global longitudinal strain increased overall after TAVI (−13.2 [8.4–16.6] vs −15.1 [9.4–17.8], p=0.047).

Conclusions

LFLGAS is associated with impaired coronary microvascular function compared with NFHGAS. Combined invasive assessment of microvascular function and advanced non-invasive imaging contributed to define different AS phenotypes. CMD was associated with low-flow state, left atrial dysfunction and reduced cardiac efficiency in patients with AS.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Abbott Vascular

Angiography derived index of microvascular resistance (IMR) in Takotsubo syndrome

Background and purpose

Coronary microvascular dysfunction (CMD) has been proposed as a key driver in the etiopathogenesis of Takotsubo syndrome (TTS), likely related to an “adrenergic storm” upon a susceptible microvascular circulation. The aim of our manuscript was to assess and quantify CMD in patients with TTS through angiography-derived index of microcirculation (IMR) and evaluate its correlation with clinical presentation.

Methods

Coronary angiograms of 41 consecutive TTS patients were retrospectively offline analyzed to derive angiography-based indices of CMD. Three recently developed indices (NH-IMRangio, AngioIMR and A-IMR) were calculated and compared based on Quantitative Flow Reserve (QFR) analysis. CMD was defined as an IMRangio ≥25 units. The correlation between CMD and clinical presentation and outcomes was then assessed.

Results

Median age was 76 years, 85.7% were women and mean left ventricular ejection fraction (LVEF) at first echocardiogram was 41.2%. Angiography-derived IMR was higher in Left Anterior Descending artery (LAD) than Circumflex artery (LCX) and Right Coronary artery (RCA) with either NH-IMRangio (52.7 vs 35.3 vs 41.4), AngioIMR (47.2 vs 31.8 vs 37.3) or A-IMR (52.7 vs 36.1 vs 41.8). All patients presented CMD with angiography-derived IMR ≥25 in at least one territory with each formula. Angiography-derived IMR in LAD territory was significantly higher in patients presenting with LVEF impairment (≤40%) than in those with preserved ventricular global function (NH-IMRangio: 59.3 vs 46.3, p. value=0.030; AngioIMR: 52.9 vs 41.4, p-value=0.037; A-IMR: 59.2 vs 46.3, p-value=0.035).

Conclusion

CMD, assessed with angiography-derived IMR, is a common finding in TTS and it is inversely correlated with LV function. The available formulas have a substantial superimposable diagnostic performance in assessing coronary microvascular function.

Funding Acknowledgement

Type of funding sources: None.

Spontaneous, independent, single-center renal denervation registry of a resistant hypertension multidisciplinary team

Background

Uncontrolled resistant hypertension (URH) is defined as PAS ≥140mmHg despite the adherence to at least 3 maximally tolerated doses of antihypertensive medications. In the adult population URH is a common condition with a prevalence that ranges between 10–15% and is related with poor prognosis and higher risk of major adverse cardiovascular events.

Renal sympathetic denervation (RDN) has recently proved efficacy in different hypertensive subsets of patients. However, patients with chronic kidney disease (CKD) IIIB-V stages (i.e. glomerular filtrate rate <45 ml/min) have been systematically excluded from randomized clinical trials (RCT).

Purpose

To evaluate the safety and the efficacy of RDN in a daily practice population of patients with URH on top of medical therapy, including patients with renal function impairment (GFR<45ml/min).

Methods

Consecutive unselected patients with URH undergoing RDN were enrolled. Indication of RDN was assessed in a multidisciplinary team involving cardiologist, nephrologist and hypertension specialists, after secondary forms of hypertension had been excluded. Efficacy was defined as the inter-individual change of office (OBP) and ambulatory blood pressure monitoring (ABPM) at 3, 6 and 12 months after RDN. Safety as the absence of any device-related major complication (BARC classification), end-stage renal disease, stroke, acute myocardial infarction and any cause of death within 1 month of the procedure. Safety and efficacy profile was assessed in patients with an estimated GFR below 45 ml/min/1.73 m2.

Results

Seventy-two patients underwent RDN for URH from 2012 to 2022. The population presented with multiple comorbidities and target organ damage: almost 50% were smoker, 43% diabetic, 33% PAD, 25% CAD and 60% CKD. Isolated systolic hypertension prevalence was 53%. The average number of antihypertensive medications at baseline was 5.3±1.1. Baseline OBP and ABPM were 158.8/86.6±23.4/15.3 mmHg and 151.4/87.6±18.8/14.2 mmHg, respectively. The vast majority of the procedures were performed with tetrapolar radio-frequency catheter (91.7%), with 37.3±14.3 number of ablations per procedure. The average amount of contrast medium was 72.1±38.1 ml. At 12-month follow-up a significant reduction of office and ambulatory systolic BP, respectively by −15.66±29.73 mmHg (P<0.01) and by −11.3±23.1mmHg (P<0.05), was noticed. BP reduction at 12-month follow-up among patients with eGFR <45 ml/min was similar to that obtained in patients with higher eGFR. No major complications were observed and renal function was stable up to 12 months, even in patients with lowest eGFR at baseline.

Conclusion(s)

RDN is safe and feasible in patients with URH on top of medical therapy, even in a high-risk CKD population with multiple comorbidities. Our experience underlines the central role of multidisciplinary team evaluation for the targeted management of uncontrolled resistant hypertension.

Funding Acknowledgement

Type of funding sources: None.

P73 ANGIOGRAPHY–DERIVED INDEX OF MICROVASCULAR RESISTANCE (IMR–ANGIO) IN TAKOTSUBO SYNDROME

Introduction

Coronary microvascular dysfunction (CMD) has been proposed as a key driver in the etiopathogenesis of Takotsubo syndrome (TTS), likely related to an “adrenergic storm” upon a susceptible microvascular circulation. The aim of our manuscript was to assess and quantify CMD in patients with TTS through non–invasive angio–derived index of microcirculation (IMRangio) and evaluate its correlation with clinical and instrumental presentation.

Methods

41 consecutive TTS patients were retrospectively analyzed. Three different formulas for compute Non–Hyperemic IMRangio (NH–IMRangio) derived by 3D–Quantitative Coronary Angiography (3D–QCA) and Quantitative Flow Reserve (QFR) analysis were used according to each fluidodynamic mathematical expression as reported by respective authors. CMD was defined as an IMRangio ≥ 25. The correlation between NH–IMRangio and clinical presentation and the comparation between the three formulas were provided.

Results

Median age was 76 years, 85.7% were women and mean left ventricular ejection fraction (LVEF) at first echocardiogram was 41.2%. NH–IMRangio was higher in Left Anterior Descending artery (LAD) than Circumflex artery (CX) and Right Coronary artery (RCA) with either NH–IMRangio 1 (52.7 vs 35.3 vs 41.4), NH–IMRangio 2 (47.2 vs 31.8 vs 37.3) or NH–IMRangio 3 (52.7 vs 36.1 vs 41.8). All patients presented CMD with NH–IMR angio ≥ 25 in at least one territory with each formula. NH–IMRangio in LAD territory was significantly higher in patients presenting with LVEF impairment (≤40%) than in those with preserved ventricular global function (NH–IMRangio LAD 1: 59.3 vs 46.3, p. value=0.030; NH–IMRangio LAD 2: 52.9 vs 41.4, p–value=0.037; NH–IMRangio LAD 3: 59.2 vs 46.3, p–value=0–035). Association between NH–IMRangio computed in LAD and LVEF showed a moderate correlation (NH–IMRangio 1: r = –0,3485, Rho = 0,1214, p = 0,0256; NH–IMRangio 2: r = –0,3513; Rho = 0,1234, p = 0,0256; NH–IMRangio 3: r = –0,3326, Rho = 0,1106, p = 0,0336). Finally, Bland–Altman plot analysis showed good agreement between NH–IMRangio 1 and 3, while NH–IMRangio 2 showed a consistent bias of –5 units against both NH–IMRangio 1 and NH–IMRangio 2 with increasing difference at higher absolute values.

Conclusion

CMD, assessed with NH–IMRangio, is a common finding in TTS and it is inversely correlate with LVEF dysfunction. The available formulas for NH–IMRangio computation have a substantial superimposable diagnostic performance in assessing CMD.