Calcium Modifications Therapies in Contemporary Percutaneous Coronary Intervention

Coronary artery calcifications (CAC) has been known to be associated with worse Percutaneous Coronary Intervention (PCI) short- and long-term outcomes. Nowadays with the increased prevalence of the risk factors leading to CAC in the population and also more PCI procedures done in older patients and with the growing number of higher risk cases of chronic total occlusion (CTO) PCI and PCI after coronary artery bypass grafting(CABG), severe cases of CAC are now encountered on a daily basis in the catheterization lab and remain a big challenge to the interventional community, making it crucial to identify cases of severe CAC and plan a CAC PCI modification strategy upfront. Improved CAC detection with intravascular imaging helped identifying more of these severe CAC cases and predicting response to therapy and stent expansion based on CAC distribution in the vessel. Multiple available therapies for CAC modification has evolved over the years, familiarity with the specifics and special considerations and limitations of each of these tools is essential in the choice and application of these therapies when used in severe CAC treatment. In this review we discuss CAC pathophysiology, modes of detection, and different available therapies for CAC modification.

662 Physiological and angiographic outcomes of PCI in calcified lesions after rotational atherectomy or intravascular lithotripsy

Aims Percutaneous coronary interventions (PCI) in calcified coronary artery lesions are associated with impaired stent expansion, higher rate of periprocedural complications and cardiac mortality. Lesion preparation using calcium modifying techniques such as Rotational Atherectomy (RA) or Intravascular Lithotripsy (IVL) has been advocated. Studies comparing these technologies are lacking. We aimed to compare the in-stent pressure gradient, evaluated by virtual fractional flow-reserve, in calcific lesions treated using either RA or IVL. Methods and results Patients undergoing either RA- or IVL-assisted PCI from two European centres were included. Propensity score matching (1:2) was performed to control for potential bias. Primary outcome was post-PCI in-stent pressure gradient calculated by virtual fractional flow reserve (vFFRgrad). Secondary outcomes included the proportion of patients with complete functional revascularization defined as of distal vFFR post PCI (vFFRpost) ≥0.90. From a cohort of 210 patients, 105 matched patients (70 RA and 35 IVL) were included. Pre-PCI vFFR did not differ between groups (0.65 ± 0.13 RA and 0.67 ± 0.11 IVL). After PCI, in-stent pressure gradients was significantly lower in the IVL group (0.032 ± 0.026 vs. 0.043 ± 0.026 in the RA group, P = 0.024). The proportion of vessels with functional complete revascularization was similar between the two groups (32.9% vs. 37.1% in the RA and IVL group, respectively; P = 0.669). Conclusions Calcific lesions preparation with IVL is effective and resulted in improved in-stent pressure gradient compared to RA. Approximately one third of the patients undergoing PCI for a severely calcified lesion achieved functional revascularization with no difference between rotational RA and IVL. 662 FigureIn stent gradients after RA and IVL. (A) Box plot depicting the distribution of the in-stent pressure gradient vFFRgrad between the two groups. (B) Cumulative frequency distribution curves demonstrating lower vFFRgrad after intravascular lithotripsy compared to rotational atherectomy. RA, rotational atherectomy; IVL, intravascular lithotripsy; vFFRgrad, in-stent pressure gradient.

Randomized non-inferiority TrIal comParing reverse T And Protrusion versus double-kissing and crush Stenting for the treatment of complex left main bifurcation lesions

Background The treatment of left main bifurcation stenoses remains challenging. Aims We compare the “Reverse T and Protrusion” (reverse-TAP) technique to Double-Kissing and crush (DK-crush). Methods The study was designed as non-inferiority trial, the primary endpoint was percentage stent expansion in the ostial side branch at optical coherence tomography. Results 52 consecutive patients (13 females, 17 diabetics, Syntax score 25 [22–29]) with complex coronary bifurcation lesions of the left main were randomized in a 1:1 ratio to Reverse-TAP or DK-crush stenting. The intervention was performed according to protocol in all patients in both randomization groups. Side branch stent expansion was 75 [67–90]% in the DK-crush group and 86 [75–95]% in the reverse-TAP group (one-sided 97.5% lower parametric confidence interval: − 0.28%; P < 0.01 for non-inferiority; P = 0.037 for superiority). Side branch balloon pressure during final kissing was higher in the DK-crush group (14 [12–16] vs. reverse-TAP: 13 [12–14]; P = 0.043). Procedural time was shorter with reverse-TAP (DK-crush: 32 [24–44] min vs reverse–TAP: 25 [22–33] min; P = 0.044). Other procedural parameters were not different between groups. There was no difference in any of the safety endpoints up to 1 month. Conclusions A reverse-TAP strategy for the interventional treatment of complex coronary lesions was non-inferior and superior to DK-crush for the primary endpoint side branch expansion while requiring less time. A larger study testing long-term clinical outcomes is warranted. Trail Registration NCT: NCT03714750. Graphical abstract

Bail-out intravascular lithotripsy for severe stent underexpansion during primary angioplasty: a case report

Background Intravascular lithotripsy is safe and effective for the treatment of de novo coronary artery calcifications. Its bail-out use in acute coronary syndrome and for underexpanded stents, although currently off-label, could be the best option when other conventional techniques fail. Case summary A patient with an inferior ST-segment elevation myocardial infarction underwent a primary percutaneous coronary intervention. Stent underexpansion due to a heavily calcified lesion was refractory to high-pressure balloon dilatations. Complete stent expansion was achieved with intravascular lithotripsy, as evidenced by intravascular ultrasound, and no acute complications occurred. Discussion Treatment strategies for stent underexpansion due to coronary artery calcifications are still debated. High-pressure non-compliant balloon dilatations are rarely sufficient to gain a complete stent expansion. Rotational and orbital atherectomy are contraindicated in presence of thrombus. Given the possible risks of stent damages, intravascular lithotripsy is currently not indicated in acutely deployed stents but could be the best bail-out technique for otherwise undilatable stents due to severely calcified plaques.

Impact of Intravascular Ultrasound–Guided Optimal Stent Expansion on 3-Year Hard Clinical Outcomes

Background: Although stent underexpansion on intravascular ultrasound (IVUS) has been a major predictor for adverse outcomes in previous studies, these studies have primarily focused on angiographic restenosis or repeat revascularization with short-term follow-up. This study sought to evaluate the long-term benefit of different criteria for IVUS-defined optimal stent expansion on hard clinical outcomes. Methods: From the pooled data of 2 randomized trials, IVUS-XPL (Impact of Intravascular Ultrasound Guidance on the Outcomes of Xience Prime Stents in Long Lesions) and ULTIMATE (Intravascular Ultrasound Guided Drug Eluting Stents Implantation in All-Comers Coronary Lesions) that compared IVUS- versus angiography-guided drug-eluting stent implantation, a total of 1254 patients with IVUS-guided drug-eluting stent implantation into 1484 long lesions (implanted stent length, ≥28 mm) were included. Different criteria for IVUS-defined optimal stent expansion based on minimum stent area (MSA) as an absolute measure or MSA relative to reference lumen area were applied and validated. The primary end point was composite of cardiac death, target lesion–related myocardial infarction, or stent thrombosis at 3 years. Results: The rate of the primary end point was lower in patients with optimal stent expansion versus those without optimal stent expansion according to 3 IVUS-defined optimal stent expansion criteria: MSA >5.5 mm 2 (0.5% versus 2.2%; hazard ratio, 0.21 [95% CI, 0.06–0.75]; P =0.008), MSA >5.0 mm 2 (0.6% versus 2.6%; hazard ratio, 0.24 [95% CI, 0.09–0.68]; P =0.003), and MSA/distal reference lumen area >90% (0.5% versus 2.4%; hazard ratio, 0.32 [95% CI, 0.12–0.88]; P =0.019). Achieving other relative expansion criteria, MSA/distal reference lumen area >100% or 80% or MSA/average reference lumen area >90% or 80%, was not associated with a reduction in hard clinical events. Conclusions: In patients undergoing IVUS-guided drug-eluting stent implantation for long lesions, achieving optimal stent expansion of MSA >5.5 mm 2 , >5.0 mm 2 , or MSA/distal reference lumen area >90% was associated with improved long-term hard clinical outcomes.

Quantification of noncircular stent expansion after TAVR into a pathological annulus and its impact on paravalvular leakage

Patients undergoing transcatheter aortic valve replacement (TAVR) may suffer severe clinical complications, caused by paravalvular leakage (PVL) which is defined as leakage between TAVR and aortic annulus. PVL is often facilitated by a severely calcified annulus. This limits the expansion of a self-expandable TAVR stent. To assess TAVR performance in terms of leakage, measurement of regurgitation fraction in a pathophysiological annulus is recommended according to ISO 5840. For this purpose, a configuration of a circular annulus with a calcification nodule has been proposed in the recently published ISO 5840. The impact of the proposed pathophysiological annulus model on the expansion of self-expandable TAVR stents and on the regurgitation fraction was investigated in this study. For this purpose, two commercially available selfexpandable TAVRs (Evolut R and Portico) were implanted in a calcified annulus model. Circular expansion of the TAVR stents was investigated based on μCT scans of the implanted TAVR. The calcification-induced area in which retrograde flow can occur during diastole was detected. These results were then compared with the experimentally determined regurgitation fraction obtained from pulse duplicator tests. The results of the μCT scans showed a continuous leakage area in the region of the annulus for the Evolut R compared to a locally larger leakage area of the Portico, which, however, reattaches to the annulus in the distal inflow region. The hydrodynamic measurements confirmed a smaller leakage in the pathological annulus for the Portico. In summary, it can be assumed that a continuous leakage area in the TAVR stent inflow region encourages the PVL of TAVR.

Assessment of stent optimization in clinical practice using optical coherence tomography: a multicentric observational study

Background Stent under-expansion obtained at the time of percutaneous coronary intervention (PCI) has been shown to be associated with worse outcomes. Purpose We sought to define OCT assessed optimal stent expansion index which associates with lower incidence of major adverse cardiac events (MACE) during follow-up in a sample of patients stented at five high volume centers of central Europe. Methods We analyzed 370 lesions stented during the period between 2012 and 2018, with their final procedural results imaged using optical coherence tomography (OCT). QIvus Research Edition v3.1 (Medis, Leiden, NL) was used for OCT analysis. The stented segment was split in two equal halves. Stent expansion index (SEI) was calculated for both halves separately by dividing minimum stent area by the mean reference lumen area [(proximal reference area + distal reference area)/2]. Smallest of the two prevailed as the SEI of that case. MACE during post-PCI follow-up was defined as composite of all-cause death, myocardial infarction, stent thrombosis and target lesion revascularization. Data is expressed as mean±SD or median (Interquartile range). Incidence of subsequent MACE is expressed as crude rates (%). Results A total of 316 cases (370 lesions), aged 64.6±11.7 years were included for OCT analysis. Of them, 78.8% were males, 22.8% were diabetics, 75.9% were hypertensives while 35.1% had family history of coronary artery disease. 38.0% of the cases had acute coronary syndrome at presentation. 62.4% of treated lesions were complex (Type B2/C). A mean of 1.11±0.34 stents/scaffolds were implanted per treated lesion. Analyzed segment length was 20.4 (15.17, 27.0) mm. Minimal stent area (MSA) in the overall stented segment was 6.02 mm2 (4.65, 7.93). Median stent expansion index (minimum) was 0.79 (0.71, 0.86). Median follow-up duration was 557 days (326, 1,096). 47 lesions (12.7%) suffered MACE during follow-up. Receiver operating characteristic (ROC) curve analysis using Youden's rule identified 0.84 as SEI cut-off powered to predict post-PCI MACE (AUC= 0.60, sensitivity= 0.85, specificity= 0.34). MACE was observed in 38/249 (15.3%) of lesions with SEI≤0.84 and in 9/121 (7.4%) of lesions with SEI&gt;0.84 (p=0.03). Univariate regression analysis of MACE revealed significant association with SEI≤0.84 (OR=2.2, 95% CI=1.1–4.8, p=0.04) Adaptive Lasso regression identified SEI≤0.84 (OR=4.1, 95% CI=1.3–12.6, p=0.02) and coronary calcification at baseline (OR=2.7, 95% CI=1.1–6.6, p=0.03) as independent predictors of MACE during follow-up. Kaplan-meier curve for MACE free survival with optimal SEI (n=121) and sub-optimal SEI (n=249) subgroups using SEI cut-off of 0.84, however showed modest separation (p=0.11). Conclusions The present study identified SEI&gt;0.84 associated with lower incidence of MACE as optimal cut-off in daily practice. Along with SEI of ≤0.84, coronary calcification was also significantly associated with MACE during post PCI follow-up. FUNDunding Acknowledgement Type of funding sources: None.

Intravascular Ultrasound–Derived Calcium Score to Predict Stent Expansion in Severely Calcified Lesions

Background: Coronary calcification inhibits stent expansion. We sought to establish an intravascular ultrasound–derived calcium score to predict stent underexpansion. Methods: This is a retrospective observational study including de novo lesions that underwent intravascular ultrasound–guided stenting and had maximum superficial calcium angle >270°. Lesions with angiographic calcium not treated with atherectomy or scoring/cutting balloon before stent implantation were randomly divided into derivation and validation cohorts. The end point was stent expansion (minimum stent area/average of reference lumen area) at the maximum calcium site, and stent expansion <70% was considered underexpansion. Results: The morphological characteristics associated with stent underexpansion in derivation cohort were (1) superficial calcium angle >270° longer than 5 mm (regression coefficient, −13.0 [95% CI, −18.1 to −7.8], P <0.0001), (2) 360° of superficial calcium (regression coefficient, −14.2 [95% CI, −22.8 to −5.5], P =0.001), (3) calcified nodule (regression coefficient, −8.3 [95% CI, −14.3 to −2.2], P =0.007), and (4) vessel diameter <3.5 mm (regression coefficient, −9.4 [95% CI, −16.0 to −2.7], P =0.006). The calcium score (0-4) was significantly correlated with poor stent expansion (regression coefficient, −8.1 [95% CI, −10.5 to −5.7], P <0.0001) in the validation cohort as well as in the atherectomy cohort (regression coefficient, −4.8 [95% CI, −7.2 to −2.5], P <0.0001) with significant interaction between validation and atherectomy cohorts ( P interaction =0.02). In lesions without angiographic calcium, all calcium severity parameters were less than in the validation cohort, and stent underexpansion was observed in only 1.5% (1/67) of lesions. Conclusions: This intravascular ultrasound calcium score provides the interventionalists with a reliable tool to identify calcified stenoses at risk for stent underexpansion and requiring adjunctive calcium modification before stent implantation.

Endovascular therapy for severely calcified plaque at the superficial femoral artery using myocardial biopsy forceps

Background Currently, the success rate of EVT for treating CTO of the SFA is high; however, EVT is still found to be insufficient in treating CTOs with severely calcified lesions. Even if the guidewire crosses the lesion, the calcifications may still cause difficulties during stent expansion. Main text A 78-year-old male had been reported to have intermittent claudication with chronic total occlusion (CTO) of the right superficial femoral artery (SFA). Angiography revealed severely calcified plaque (Angiographic calcium score: Group4a [1]) at the ostium of the SFA. Stenting posed a risk of underexpansion, causing the plaque to shift to the deep femoral artery. we decided to remove the calcified plaque using biopsy forceps. After removing the extended calcified plaque, the guidewire could cross easily, and the self-expandable stent was well dilated without causing the plaque to shift to the DFA. Conclusions Biopsy forceps may be used in some endovascular cases to remove severely calcified lesions. To ensure the safety of the patient, the physician must be adept at performing this technique before attempting it.