Coronary lithotripsy for the treatment of underexpanded stents: the international & multicentre CRUNCH registry.

BACKGROUND: Stent underexpansion increases the risk of cardiac adverse events. At present, there are limited options to treat refractory stent underexpansion. In this context, the intravascular lithotripsy (IVL) system might be a safe and effective strategy. AIMS: We aimed to evaluate the safety and efficacy of IVL in addressing resistant stent underexpansion due to heavy underlying calcification. METHODS: This was an international multicentre registry including patients receiving IVL therapy to treat stent underexpansion from December 2017 to August 2020. Angiographic and intracoronary imaging data were collected. The efficacy endpoint was device success (technical success with a final percentage diameter stenosis <50%). The safety endpoint was in-hospital major adverse cardiac events (MACE). RESULTS: Seventy patients were included, the mean age was 73±9.2 years and 76% were male. The median time from stent implantation to IVL therapy was 49 days (0-2,537). Adjuvant treatment with non-compliant balloon dilatations pre- and post-IVL was performed in 72.3% and 76.8% of patients, respectively, and additional stenting was performed in 22.4%. Device success was 92.3%. Minimum lumen diameter increased from 1.49±0.73 mm to 2.41±0.67 mm (p<0.001) and stent expansion increased by 124.93±138.19% (p=0.016). No IVL-related procedural complications or MACE were observed. The use of bailout IVL therapy directly after stenting and the presence of ostial underexpanded lesions negatively predicted lumen diameter gain. CONCLUSIONS: Coronary lithotripsy is safe and effective in increasing lumen and stent dimensions in underexpanded stents secondary to heavily calcified lesions.

Near-infrared spectroscopy to predict plaque progression in plaque-free artery regions.

BACKGROUND: Positive near-infrared spectroscopy (NIRS) signals might be encountered in areas without evident artery wall thickening, being typically perceived as artefacts. AIMS: We aimed to evaluate the utility of NIRS to identify artery wall regions associated with an increase in wall thickness (WT) as assessed by serial intravascular ultrasound (IVUS) and optical coherence tomography (OCT). METHODS: In this prospective, single-centre study, patients presenting with acute coronary syndrome (ACS) underwent NIRS-IVUS and OCT assessment of a non-culprit artery at baseline and 12-month follow-up. For each vessel, 1.5 mm segments were identified, matched and divided into 45 sectors. The relationship between the change in IVUS-based WT (DWT) and the presence of NIRS-positive signals and OCT-detected lipid was evaluated using linear mixed models. RESULTS: A total of 37 patients (38 vessels, 6,936 matched sectors) were analysed at baseline and 12 months. A total of 140/406 (34.5%) NIRS (+) sectors and 513/1,575 (32.6%) OCT-lipid (+) sectors were found to be located in thin (WT<0.5 mm) wall sectors. In the thin wall sectors, an increase in WT was significantly more pronounced in NIRS (+) vs NIRS (-) sectors (0.11 mm vs 0.06 mm, p<0.001). In the thick wall sectors, there was a decrease in WT observed that was less pronounced in the NIRS (+) versus NIRS (-) sectors (-0.08 mm vs -0.09 mm, p<0.001). Thin wall NIRS (+) OCT-lipid (+) sectors showed significant wall thickening (DWT=0.13 mm). CONCLUSIONS: NIRS-positive signals in otherwise non-diseased arterial walls as assessed by IVUS could identify vessel wall regions prone to WT increase over 12-month follow-up. Our observations suggest that NIRS-positive signals in areas without evident wall thickening by IVUS should no longer be viewed as benign or imaging artefact.

Impact of intravascular ultrasound findings in patients with a post PCI fractional flow reserve ≤0.85 on 2 year clinical outcome.

BACKGROUND: Patients with a low post PCI fractional flow reserve (FFR) are at increased risk for future adverse cardiac events. The aim of the present study was to assess the impact of specific intravascular ultrasound (IVUS) findings in patients with a low post percutaneous coronary intervention (PCI) FFR on long-term clinical outcome. METHODS: In a subgroup analysis, 100 vessels with an FFR value ≤0.85 underwent post PCI IVUS to further assess the potential determinants for low post PCI FFR. No further action was taken to improve post PCI FFR. The primary endpoint of this study was the event free survival of target vessel failure (TVF) at two years in patients with a post PCI FFR ≤0.85, which was defined as a composite of cardiac death, target vessel myocardial infarction or target vessel revascularization. RESULTS: In patients with a post PCI FFR ≤0.85, TVF free survival rates were 88.5% vs. 95.5% for patients with versus without residual proximal lesions and 88.2% vs. 95.5% for patients with versus without residual distal lesions respectively (HR = 2.53, 95% confidence interval (CI) 0.52-12.25, p = .25 and HR = 2.60, 95% CI 0.54-12.59, p = .24 respectively). TVF free survival was 92.8% vs. 93.5% in patients with versus without stent underexpansion >20% (HR = 1.01, 95% CI 0.21-4.88, p = .99) and 89.3% vs. 97.8% in patients with versus without any residual focal lesion including lumen compromising hematoma (HR = 4.64, 95% CI 0.55-39.22, p = .18). CONCLUSION: Numerically higher TVF rates were observed in patients with a post PCI FFR ≤0.85 and clear focal residual disease as assessed with IVUS.

Revascularization Strategies in Patients Presenting With ST-Elevation Myocardial Infarction and Multivessel Coronary Disease.

The optimal revascularization strategy for residual coronary stenosis following primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease (MVD) remains controversial. This is a retrospective single-centre study including patients with STEMI and MVD. Based on the revascularization strategy, 3 groups were identified: (1) culprit only (CO), (2) ad hoc multivessel revascularization (MVR), and (3) staged MVR. Clinical outcomes were compared in terms of major adverse cardiac events (MACE), a composite of cardiac death, any myocardial infarction, and any unplanned revascularization at a long-term follow-up. A total of 958 patients were evaluated, 489 in the CO, 254 in the ad hoc, and 215 in the staged group. In the staged group, 65.6% of the patients received planned percutaneous coronary intervention, 9.7% coronary artery bypass grafting, 8.4% no further intervention after lesion reassessment, and in 16.3% an event occurred before the planned procedure. At 1,095 days, MACE was 36.1%, 16.7%, and 31% for CO, ad hoc, and staged groups, respectively. A MVR strategy was associated with lower rate of all-cause death compared with CO (HR 0.50; 95%CI [0.31 to 0.80]; p = 0.004). Complete revascularization reduced the rate of MACE (HR 0.30 [0.21 to 0.43] p < 0.001) compared with incomplete revascularization. Ad hoc MVR had lower rate of MACE compared with staged MVR (HR 0.61 [0.39 to 0.96] p = 0.032) mainly driven by less unplanned revascularizations. In conclusion, in patients with STEMI and MVD, complete revascularization reduced the risk of MACE. Ad hoc MVR appeared a reasonable strategy with lower contrast and stent usage and costs.

Impact of bioresorbable scaffold design characteristics on local haemodynamic forces: an ex vivo assessment with computational fluid dynamics simulations.

AIMS: Bioresorbable scaffold (BRS) regions exposed to flow recirculation, low time-averaged wall shear stress (TAWSS) and high oscillatory shear index (OSI) develop increased neointima tissue. We investigated haemodynamic features in four different BRSs. METHODS AND RESULTS: Fantom (strut height [SH] = 125 µm), Fantom Encore (SH = 98 µm), Absorb (SH = 157 µm) and Magmaris (SH = 150 µm) BRSs were deployed in phantom tubes and imaged with microCT. Both 2D and 3D geometrical scaffold models were reconstructed. Computational fluid dynamics (CFD) simulation was performed to compute TAWSS and OSI. Thicker struts had larger recirculation zones and lower TAWSS in 2D. Absorb had the largest recirculation zone and the lowest TAWSS (240 µm and -0.18 Pa), followed by Magmaris (170 µm and -0.15 Pa), Fantom (140 µm and -0.14 Pa) and Fantom Encore (100 µm and -0.13 Pa). Besides strut size, stent design played a dominant role in 3D. The highest percentage area adverse TAWSS (<0.5 Pa) and OSI (>0.2) were found for Fantom (56% and 30%) and Absorb (53% and 33%), followed by Fantom Encore (30% and 25%) and Magmaris (25% and 20%). Magmaris had the smallest areas due to a small footprint and rounded struts. CONCLUSIONS: Due to stent design, both Fantom Encore and Magmaris showed smaller TAWSS and OSI than Fantom and Absorb. This study quantifies which scaffold features are most important to reduce long-term restenosis.

Long-term outcome in patients treated with first- versus second-generation drug-eluting stents for the treatment of unprotected left main coronary artery stenosis.

OBJECTIVE AND BACKGROUND: The study aim is to provide long-term clinical outcome after percutaneous coronary intervention (PCI) for unprotected left main coronary arteries (ULMCA) stenosis with the first-generation (1st -gen) drug-eluting stents (DES) in comparison to 2nd -gen DES, since this is largely unknown. METHODS: Between May 2002, and December 2014, a consecutive series of 656 all-comer patients underwent a PCI for ULMCA stenosis at the Erasmus Medical Center. A total of 235 patients were treated with 1st -gen DES, while a total of 421 patients were treated with 2nd -gen DES. RESULTS: Overall, the population consisted of 73% males and 58% presented with an acute coronary syndrome. Median follow-up time was 1,361 days (range from 0 to 5,031). At 5 years, the cumulative incidence of major adverse clinical events (the primary composite endpoint of all-cause death, any myocardial infarction or target lesion revascularization; MACE) did not differ between 1st - and 2nd -gen DES (36.8 vs. 38.6%, respectively, Log Rank p = .79, adjusted hazard ratio [HR] = 1.28 [95% confidence interval (CI) 0.94-1.74]). No difference was found in the individual endpoints of all-cause mortality (29.5 vs. 29% respectively, p = .88, adjusted HR = 1.19 [95% CI, 0.84-1.68]), target vessel myocardial infarction (5.0 vs. 8.4%, p = 0.17, adjusted HR = 1.75 [95% CI, 0.78-3.96]) and target lesion revascularization (8.1 vs. 9.8%, p = .94, adjusted HR = 1.16 [95% CI, 0.59-2.29]) between the 1st - and 2nd -gen DES cohorts, respectively. CONCLUSIONS: In this large cohort of consecutive patients treated for ULMCA stenosis, no significant differences were found in the safety and efficacy of 1st versus 2nd -gen DES at 5 years follow-up.

Serial invasive imaging follow-up of the first clinical experience with the Magmaris magnesium bioresorbable scaffold.

OBJECTIVES: To assess the performance of the commercially available Magmaris sirolimus-eluting bioresorbable scaffold (BRS) with invasive imaging at different time points. BACKGROUND: Coronary BRS with a magnesium backbone have been recently studied as an alternative to polymeric scaffolds, providing enhanced vessel support and a faster resorption rate. We aimed to assess the performance of the commercially available Magmaris sirolimus-eluting BRS at different time points. METHODS: A prospective, single-center, nonrandomized study was performed at the Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands. Six patients with stable de novo coronary artery lesions underwent single-vessel revascularization with the Magmaris sirolimus-eluting BRS. Invasive follow-up including intravascular imaging using optical coherence tomography (OCT) was performed at different time points. RESULTS: At a median of 8 months (range 4-12 months) target lesion failure occurred in one patient. Angiography revealed a late lumen loss of 0.59 ± 0.39 mm, a percentage diameter stenosis of 39.65 ± 15.81%, and a binary restenosis rate of 33.3%. OCT showed a significant reduction in both minimal lumen area (MLA) and scaffold area at the site of the MLA by 43.44 ± 28.62 and 38.20 ± 25.74%, respectively. A fast and heterogeneous scaffold degradation process was found with a significant reduction of patent struts at 4-5 months. CONCLUSIONS: Our findings show that the latest iteration of magnesium BRS suffers from premature dismantling, resulting in a higher than expected decrease in MLA.

Incidence and predictors of outcomes after a first definite coronary stent thrombosis.

AIMS: Stent thrombosis (ST) is a rare but potentially fatal complication of coronary artery stenting. Little is known about the optimal treatment strategy at the time of an ST event. We aimed to identify the incidence and predictors of adverse cardiac events after treatment of a definite ST. METHODS AND RESULTS: A total of 695 patients with definite ST were included between 1996 and 2017 in two academic medical centres. The primary endpoint was MACE, the composite of cardiac death, myocardial infarction (MI) and target vessel revascularisation (TVR). Mean age was 62.8±12.1 years and 76.3% were male. ST occurred at a median of 22 days (IQR 3-551 days); 50.8% were early and 49.2% were late/very late ST. At 60-month follow-up, the MACE rate was 43.7%, cardiac death 19.5%, MI 17.9%, TVR 24.8%, and repeat definite ST was 12.1% (10.5% in target vessel). Independent predictors of MACE were cardiogenic shock (HR 2.54, 95% CI: 1.75-3.70; p<0.001), ST in the LAD (HR 1.76, 95% CI: 1.32-2.35; p<0.001), prior CVA/TIA (HR 1.68, 95% CI: 1.08-2.62; p=0.020), peripheral vascular disease (HR 1.55, 95% CI: 1.00-2.39; p=0.046), multivessel disease (HR 1.53, 95% CI: 1.12-2.08; p=0.007), and final TIMI flow 2-3 (HR 0.54, 95% CI: 0.34-0.85; p=0.009). No specific treatment of ST influenced MACE; however, new-generation P2Y12 inhibitors reduced the risk of MI (HR 0.56, 95% CI: 0.32-0.99; p=0.049). CONCLUSIONS: The incidence of adverse events remains high after a first episode of ST. New-generation P2Y12 inhibitors reduce the risk of MI. Additional stenting, GP IIb/IIIa inhibitors and thrombectomy did not improve outcomes following ST.

Stent underexpansion due to heavy coronary calcification resistant to rotational atherectomy: A case for coronary lithoplasty?

Stent underexpansion is frequently observed in calcified coronary lesions and increases the risk of future adverse cardiac events. Current plaquemodification techniques might not be suitable when calcium deposition is circumferential and deep inside the vessel wall. We report a case during which coronary lithoplasty was used as an adjuvant therapy to improve severe stent underexpansion after failed atherectomy and high-pressure non-compliant balloon dilatations.

Fractional flow reserve guided percutaneous coronary intervention optimization directed by high-definition intravascular ultrasound versus standard of care: Rationale and study design of the prospective randomized FFR-REACT trial.

BACKGROUND: Post percutaneous coronary intervention (PCI) fractional flow reserve (FFR) is a significant predictor of major adverse cardiac events (MACE). The rationale for low post procedural FFR values often remains elusive based on angiographic findings alone, warranting further assessment using an FFR pullback or additional intravascular imaging. It is currently unknown if additional interventions intended to improve the PCI, decrease MACE rates. STUDY DESIGN: The FFR REACT trial is a prospective, single-center randomized controlled trial in which 290 patients with a post PCI FFR <0.90 will be randomized (1:1) to either standard of care (no additional intervention) or intravascular ultrasound (IVUS)-directed optimization of the FFR (treatment arm). Eligible patients are those treated with angiographically successful PCI for (un)stable angina or non-ST elevation myocardial infarction (MI). Assuming 45% of patients will have a post PCI FFR <0.90, approximately 640 patients undergoing PCI will need to be enrolled. Patients with a post PCI FFR ≥ 0.90 will be enrolled in a prospective registry. The primary end point is defined as a composite of cardiac death, target vessel MI and clinically driven target vessel revascularisation (target vessel failure) at 1 year. Secondary end points will consist of individual components of the primary end point, procedural success, stent thrombosis and correlations on clinical outcome, changes in post PCI Pd/Pa and FFR and IVUS derived dimensions. All patients will be followed for 3 years. CONCLUSION: The FFR-REACT trial is designed to explore the potential benefit of HD-IVUS-guided PCI optimization in patients with a post PCI FFR <0.90 (Dutch trial register: NTR6711).

Explanation of Postprocedural Fractional Flow Reserve Below 0.85.

BACKGROUND: Fractional flow reserve (FFR) after percutaneous coronary intervention is a predictor of adverse cardiovascular events during follow-up. However, the rationale for low post procedural FFR values remains often elusive based on angiographic findings alone. METHODS AND RESULTS: FFR SEARCH (Stent Evaluated at Rotterdam Cardiology Hospital) is a prospective single-center registry in which post-percutaneous coronary intervention FFR was assessed in 1000 consecutive all-comer patients. FFR measurements were performed with a microcatheter ±20 mm distal to the most distal stent edge. In 100 vessels with a post procedural FFR ≤0.85, and 20 vessels >0.85 high definition intravascular ultrasound analysis was performed. In 100 vessels with a post-percutaneous coronary intervention FFR ≤0.85, mean post procedural FFR was 0.79±0.05. Minimal lumen area was 2.19 (1.81-3.19) mm2, mean lumen area was 5.95 (5.01-7.03) mm2, and minimal stent area was 4.01 (3.09-5.21) mm2. Significant residual focal proximal lesions were found in 29% of the assessed vessels whereas, focal distal lesions were found in 30% of the vessels. Stent underexpansion and malapposition were found in 74% and 22% of vessels, respectively. Clear focal signs of luminal narrowing were found in 54% of the vessels analyzed. Although incidences of focal lesions, underexpansion, and malapposition were similar between both cohorts, minimal stent area was significantly smaller in vessels with a post-percutaneous coronary intervention FFR ≤0.85 as compared with those with an FFR >0.85. CONCLUSIONS: In patients with a post procedural FFR ≤0.85, intravascular ultrasound revealed focal signs of luminal narrowing in a significant number of cases.