Crystalline sirolimus-coated balloon (cSCB) angioplasty in an all-comers, patient population with stable and unstable coronary artery disease including chronic total occlusions: rationale, methodology and design of the SCORE trial.

BACKGROUND: A decade ago, the iopromide-paclitaxel coated balloon (iPCB) was added to the cardiologist's toolbox to initially treat in-stent restenosis followed by the treatment of de novo coronary lesions. In the meantime, DES technologies have been substantially improved to address in-stent restenosis and thrombosis, and shortened anti-platelet therapy. Recently, sirolimus-coated balloon catheters (SCB) have emerged to provide an alternative drug to combat restenosis. METHODS: The objective of this study is to determine the safety and efficacy of a novel crystalline sirolimus-coated balloon (cSCB) technology in an unselective, international, large-scale patient population. Percutaneous coronary interventions of native stenosis, in-stent stenosis, and chronic total occlusions with the SCB in patients with stable coronary artery disease or acute coronary syndrome were included. The primary outcome variable is the target lesion failure (TLF) rate at 12 months, defined as the composite rate of target vessel myocardial infarction (TV-MI), cardiac death or ischemia-driven target lesion revascularization (TLR). The secondary outcome variables include TLF at 24 months, ischemia driven TLR at 12 and 24 months and all-cause death, cardiac death at 12 and 24 months. DISCUSSION: Since there is a wealth of patient-based all-comers data for iPCB available for this study, a propensity-score matched analysis is planned to compare cSCB and iPCB for the treatment of de novo and different types of ISR. In addition, pre-specified analyses in challenging lesion subsets such as chronic total occlusions will provide evidence whether the two balloon coating technologies differ in their clinical benefit for the patient. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT04470934.

Clinical outcomes following polymer-free sirolimus-eluting stent implantations in unselected patients: A descriptive subgroup analysis in patients with renal impairment.

Patients with chronic kidney disease (CKD are frequently excluded from coronary artery disease trials. The aim of this assessment was to study the clinical outcomes of polymer-free sirolimus-eluting stent implantations in patients with impaired renal function.Large-scale, international, single-armed, multicenter, 'all comers' observational studies (ClinicalTrials.gov Identifier: NCT02629575 and NCT02905214) were used for this post-hoc subgroup analysis to compare the clinical outcomes in patients with normal renal function (NRF) to those with renal insufficiency (CKD, dialysis dependence). The accumulated target lesion revascularization rate was the primary endpoint at 9 to 12 months whereas the accumulated major adverse cardiac event, stent thrombosis (ST) and procedural success rates were part of the secondary endpoints.There were 6791 patients with NRF, whereas 369 patients had CKD and 83 patients were dialysis dependent. The target lesion revascularization rate at 9 to 12 months was significantly higher in dialysis patients (2.1% vs 3.3% vs 6.7%, P = .011). The accumulated major adverse cardiac events rates in the dialysis and in the CKD group were significantly higher as compared to patients with NRF (13.3% vs 4.0%, P < .001; 6.5% vs 4.0%, P = .024). Finally, ST rates (NRF: 0.7%, CKD: 0.6%, dialysis: 1.3%) were not statistically different between subgroups (P = .768). All-cause cumulative mortality rates were 3.3% (CKD) and 4.0% (dialysis) respectively.Percutaneous coronary interventions with polymer-free, ultra-thin strut sirolimus-eluting stents have comparable revascularization rates in CKD and dialysis dependent patients as compared to percutaneous coronary interventions with other 2nd generation drug-eluting stents. ST and all-cause mortality rates were low as compared to available literature references.

Design and rationale for the "Me & My Heart" (eMocial) study: A randomized evaluation of a new smartphone-based support tool to increase therapy adherence of patients with acute coronary syndrome.

A novel smartphone-based patient support tool was developed to increase the adherence to antiplatelet therapy and lifestyle changes in patients after coronary angioplasty for acute coronary syndrome (ACS). The eMocial study (ClinicalTrials.gov Identifier: NCT02615704) investigates whether an electronic support tool will improve adherence to comedication and lifestyle changes in ACS patients. The primary hypothesis of this trial is that an electronic support tool can increase adherence to comedication (primary endpoint) thereby supporting positive lifestyle changes (secondary endpoints). Patients hospitalized with ACS (ST elevation myocardial infarction [STEMI], non-ST elevation myocardial infarction [NSTEMI], or unstable angina pectoris) and treated with ticagrelor coadministered with low-dose acetylsalicylic acid will be randomized 1:1 to an active group receiving the patient support tool via a smartphone-based application or to a control group without the patient support tool. Patient questionnaires to evaluate lifestyle changes and quality of life will be used at baseline and at the end of the 48-week observation phase. Patients are asked to fill out questionnaires to determine their adherence, treatment attitudes, health-care utilization and risk factors on a monthly basis. The study was started in February 2016 and the completion date is scheduled for October 2019. For final analysis 664 patients are expected be available. Preliminary baseline demographics were unstable angina pectoris (13.7%), NSTEMI (49.9%), STEMI (36.4%), male gender (86.3%), and diabetes mellitus (17.6%). Our study could significantly help to understand how inadequate adherence to antiplatelet therapy in ACS patients could be improved with a smartphone-based application.

Two-Year Mortality After Angioplasty of the Femoro-Popliteal Artery with Uncoated Balloons and Paclitaxel-Coated Balloons-A Pooled Analysis of Four Randomized Controlled Multicenter Trials.

PURPOSE: In view of a recent meta-analysis reporting increased mortality following angioplasty with paclitaxel-coated devices in peripheral arteries, we performed a patient-level 2-year mortality analysis based on pooled original data of four randomized controlled trials (THUNDER, FEMPAC, PACIFIER and CONSEQUENT). METHODS AND RESULTS: Clinical data of four randomized controlled trial were pooled to assess 2-year mortality following paclitaxel-coated balloon (PCB) angioplasty compared to angioplasty without paclitaxel (control group). A logistic regression model was applied to identify potential predictors of mortality. At two years, 13 of 185 (7.0%) patients had died in the control group and 16/184 (8.7%) in the PBC group, p = 0.55. Kaplan-Meier analysis revealed no significant difference from all-cause death at 2 years (log rank p = 0.54). Causes of death were well balanced between the groups with no pattern or trend in favour of any specific causes in the PBC group. Logistic regression revealed that treatment groups (controls or PBC) were not a predictor of 2-year mortality. The only predictor for mortality was patient age ≥ 75 years. The delivered paclitaxel doses per patient were not significantly different in patients that died and those who did not die during the 24-month follow-up (5.300 ± 4.224 µg vs. 6.248 ± 4.629 µg, p = 0.433). CONCLUSIONS: Based on original patient-level data of four pooled randomized controlled trials, we found no increase in 2-year mortality in patients treated with PCB compared to control patients treated with uncoated balloons. Causes of death were well balanced between PCB and control patients.

Comparative preclinical evaluation of a polymer-free sirolimus-eluting stent in porcine coronary arteries.

BACKGROUND:: Polymer-free drug-eluting stents (DES) without permanent-polymer coating may be associated with rapid vessel healing, providing a rationale to reduce dual-antiplatelet therapy (DAPT). The aim of the current study was to compare vessel healing of a polymer-free sirolimus-eluting stent (PF-SES), its bare metal stent (BMS) analogue to a permanent polymer-based sirolimus-eluting stent (SES) with proven effectiveness in porcine coronary arteries. MATERIAL AND METHODS:: An ultrathin-strut cobalt-chromium PF-SES, its BMS analogue and an SES with a permanent polymer were used to study vessel healing and their antistenotic potential. Stents were implanted in porcine coronary arteries for histopathologic analysis at 7, 28 and 180 days. In an additional in vitro study, the thrombogenicity of PF-SES was compared with a fluoropolymer-coated everolimus-eluting stent (EES) which demonstrated low stent thrombosis rates in numerous studies. RESULTS:: In the animal study, neointimal growth and injury scores were minimal and inflammation scores were low in the neointima and adventitia in all study groups. After 28 days, neointimal area was lowest in PF-SES when compared with SES and BMS (1.48 ± 0.55 mm² versus 2.43 ± 0.69 mm² versus 1.90 ± 0.85 mm², respectively, p < 0.05) and endothelialization of luminal surfaces was nearly complete in all groups, though SES show the least coverage with occasional adherent luminal inflammatory cells ( p > 0.05). At 180 days, neointimal area and thickness were most pronounced in SES ( p < 0.05) and comparable with BMS implantations, which were characterized by nearly completed vessel healing. PF-SES and BMS had complete endothelialization, absence of fibrin and sustained low inflammatory reaction when compared with the permanent polymer-based SES (inflammation score: PF-SES 0.41 ± 0.74 versus SES 2.52 ± 1.72 versus BMS 0.30 ± 0.65, respectively, p < 0.05 BMS versus SES). Granuloma formation and fibrin accumulation were most pronounced in SES but did not reach statistical significance, p > 0.05). In the in vitro thrombogenicity study, the PF-SES confirmed comparable antithrombogenic properties with regard to the parameters fibrin and platelet binding, and platelet aggregation when compared with the EES. CONCLUSIONS:: As compared with BMS, the ultrathin-strut cobalt-chromium PF-SES showed similar endothelialization at 28 days and comparable healing characteristics at 180 days efficacious inhibition of neointimal proliferation in porcine coronary arteries with low inflammation responses and a BMS-like endothelialization at 180 days. In addition, in an in vitro model, the PF-SES also confirmed low thrombogenicity as compared with the EES.

Efficacy and Safety of Polymer-Free Ultrathin Strut Sirolimus-Probucol Coated Drug-Eluting Stents for Chronic Total Occlusions: Insights from the Coroflex ISAR 2000 Worldwide Registry.

OBJECTIVE: Coronary revascularization in chronic total occlusion (CTO) is associated with improved clinical outcomes. The choice of the coronary stent is crucial in maintaining long-term vessel patency after CTO revascularization. We investigated the efficacy and safety of polymer-free ultrathin strut sirolimus-probucol coated drug-eluting stents (PF-SES) for CTO lesions. METHODS: Patients with CTO lesions treated with PF-SES were identified from the prospective multicenter international ISAR 2000 registry. The primary endpoint was clinically driven target lesion revascularization (TLR) at 9 months. Secondary endpoints were 9-month major adverse cardiac events (death, myocardial infarction, or TLR) (MACE) and the occurrence of stent thrombosis. RESULTS: A total of 111 patients with CTO lesions (n=127) were available for analysis. The 9-month clinical follow-up rate was 91%. The mean reference vessel diameter and lesion length were 2.76 mm ± 0.40 and 26.8 mm ± 13.1, respectively. The overall DAPT duration was 9.7 ± 2.8 months. Only one (1%) in-hospital MI was reported. The TLR and MACE rates at 9 months were 2% (2/101) and 5.9% (6/101), respectively. The 9-month accumulated rates of definite or probable stent thrombosis was 0% (0/101). CONCLUSION: Revascularizations for CTO with PF-SES are associated with low rates of TLR and MACE at 9 months with no stent thrombosis. These initial findings need to be compared with results of other new generation DES of larger studies.

Insights into coronary collateral formation from a novel porcine semiacute infarction model.

BACKGROUND: For patients with severe ischemic heart disease, complete revascularization by a percutaneous coronary intervention or coronary artery bypass grafting is often not achieved and may still cause residual angina. In case of progressive coronary artery occlusions, therapeutic arteriogenesis constitutes a promising strategy for increasing blood supply to the ischemic myocardium. Whether the formation of collaterals in the hypofused myocardium is angiogenetic in nature or based on preformed coronary artery anastomoses remains debatable. The objectives of this research were (i) the development of an appropriate research methodology to study a humanoid animal semiacute infarction model with low mortality and (ii) to answer the question of whether collateral revascularization follows a pre-existing 'blueprint'. MATERIALS AND METHODS: A porcine model was chosen in which a step-wise vessel occlusion was performed by implantation of a copper stent into the distal left anterior descending artery. Vessel occlusion and collateral development were confirmed in vivo every 14 days up to day 56 by repeated coronary angiography and myocardial perfusion measurement using cardiac MRI. After the completion of the in-vivo imaging studies, animals were euthanized and collateral growth was evaluated using microcomputer tomography. RESULTS: Our porcine model of semiacute noninvasive coronary artery occlusion confirmed the existence of preformed coronary anastomoses and the proliferation of functional vessels in hypoperfused myocardium. Repetitive intra-animal MRIs showed the functional impact of these growing collaterals. CONCLUSION: The confirmation of preformed coronary anastomoses during the process of collateralization (natural bypasses) offers a preclinical avenue to carry out arteriogenetic pharmaceutical research in patients with ischemic heart disease.

Polymer-free sirolimus-eluting stents in a large-scale all-comers population.

OBJECTIVE: The objective of this study was to assess the safety and efficacy of a polymer-free sirolimus coated, ultrathin strut drug-eluting stent (PF-SES) in an unselected patient population with a focus on acute coronary syndrome (ACS). Furthermore, stable coronary artery disease (CAD) with short (≤6 months) versus long (>6 months) dual antiplatelet therapy (DAPT) were also studied. METHODS: Patients who received PF-SES were investigated in an unselected large-scale international, single-armed, multicenter, 'all comers' observational study. The primary endpoint was the 9-month target lesion revascularisation (TLR) rate, whereas secondary endpoints included the 9-month major adverse cardiac events (MACE) and procedural success rates. A priori defined subgroups such as patients with ACS, diabetes, lesion subsets and procedural characteristics relative to DAPT were investigated. RESULTS: A total of 2877 patients of whom 1084 had ACS were treated with PF-SES (1.31±0.75 stents per patient). At 9 months, the accumulated overall TLR rate was 2.3% (58/2513). There was no significant difference between ACS and stable CAD (2.6% vs 2.1%, p=0.389). However, the overall MACE rate was 4.3% (108/2513) with a higher rate in patients with ACS when compared with the stable CAD subgroup (6.1%, 58/947 vs 3.2%, 50/1566, p<0.001). CONCLUSIONS: PF-SES angioplasty is safe and effective in the daily clinical routine with low rates of TLR and MACE in an unselected patient population. Our data are in agreement with prior clinical findings that extended DAPT duration beyond 6 months do not improve clinical outcomes in patients with stable CAD (ClinicalTrials.gov Identifier NCT02629575). TRIAL REGISTRATION NUMBER: NCT02629575.

Surrogate and clinical endpoints for studies in peripheral artery occlusive disease: Are statistics the brakes?

BACKGROUND: The aim of this review is to present the available clinical and surrogate endpoints that may be used in future studies performed in patients with peripheral artery occlusive disease (PAOD). Importantly, we describe statistical limitations of the most commonly used endpoints and offer some guidance with respect to study design for a given sample size. The proposed endpoints may be used in studies using surgical or interventional revascularization and/or drug treatments. METHODS: Considering recently published study endpoints and designs, the usefulness of these endpoints for reimbursement is evaluated. Based on these potential study endpoints and patient sample size estimates with different non-inferiority or tests for difference hypotheses, a rating relative to their corresponding reimbursement values is attempted. RESULTS: As regards the benefit for the patients and for the payers, walking distance and the ankle brachial index (ABI) are the most feasible endpoints in a relatively small study samples given that other non-vascular impact factors can be controlled. Angiographic endpoints such as minimal lumen diameter (MLD) do not seem useful from a reimbursement standpoint despite their intuitiveness. Other surrogate endpoints, such as transcutaneous oxygen tension measurements, have yet to be established as useful endpoints in reasonably sized studies with patients with critical limb ischemia (CLI). CONCLUSIONS: From a reimbursement standpoint, WD and ABI are effective endpoints for a moderate study sample size given that non-vascular confounding factors can be controlled.