Bail-out intravascular lithotripsy for the treatment of acutely underexpanded stents in heavily calcified coronary lesions: A case series

Procedural and clinical impact of intravascular lithotripsy for the treatment of peri-stent calcification

BACKGROUND

Use of intravascular lithotripsy (IVL) for treating peri-stent calcification is increasing. However, this indication remains 'off-label'. We aimed to investigate the efficacy and clinical outcomes of in-stent IVL.

METHODS

Patients from five European centers who underwent in-stent IVL were included between 2019 and 2023. Demographic, clinical, procedural and follow-up data were collected from electronic hospital records. Angiographic and intracoronary imaging (ICI) data were analyzed in a centralized core-laboratory.

RESULTS

Of 101 patients (71.2 ± 9.2 years), 56(55 %) received in-stent IVL for late stent failure (median 109 days post-PCI) due to calcific neoatherosclerosis or extra-stent calcification(late-IVL), while 45(45 %) underwent bail-out IVL due to stent infraexpasion (immediate-IVL). Both late-IVL and immediate-IVL significantly improved angiographic %diameter stenosis (73.7[59.6-89.8]% to 16.4 [10.4-26.9]%;p < 0.0001 and 28.6[22.5-43.3]% to 14.1[10.3-29.4]%;p < 0.0001, and minimum lumen area (MLA) (3.4 ± 1.2 to 8.6 ± 2.5 mm2;p < 0.002 and 5.4 ± 1.9 to 7.3 ± 1.9;p < 0.0001).Device(98 %) and procedural success(80 %) were high. MACE rates in-hospital (2 %), 30-days (3 %),6-months(5 %) and 1-year(7 %) were low and comparable in both groups. Acute diameter gain was lower in immediate-IVL (2.1 ± 0.7 mm vs. 0.5 ± 0.4 mm;p < 0.0001). This, however, was explained by significant differences in pre-IVL angiographic and ICI parameters (%diameter stenosis 73.7[59.6-89.8] vs. 28.6[22.5-43.3]%; p < 0.0001 and MLA (3.4 ± 1.2 vs 5.4 ± 1.9 mm2; p < 0.0001), whereas post-IVL percentage diameter stenosis (16.4(10.4-26.9) vs. 14.1(10.3-29.4);p = 0.914) and MLA (8.6 ± 2.5vs. 7.4 ± 1.9 mm2;p = 0.064) in late- and immediate-IVL were comparable.

CONCLUSIONS

IVL in-stent due to peri-stent calcification is an effective strategy, both late and immediately after stent implantation. Overall, MACE rates at short- and mid-term were low and comparable in both groups, although clinical findings should be taken with caution.

A Systematic Review and Meta-Analysis Including 354 Patients from 13 Studies of Intravascular Lithotripsy for the Treatment of Underexpanded Coronary Stents

Calcified coronary plaque (CCP) represents a challenging scenario for interventional cardiologists. Stent underexpansion (SU), often associated with CCP, can predispose to stent thrombosis and in-stent restenosis. To date, SU with heavily CCP can be addressed using very high-/high-pressure noncompliant balloons, off-label rotational atherectomy/orbital atherectomy, excimer laser atherectomy, and intravascular lithotripsy (IVL). In this meta-analysis, we investigated the success rate of IVL for the treatment of SU because of CCP. Studies and case-based experiences reporting on the use of IVL strategy for treatment of SU were included. The primary end point was IVL strategy success, defined as the adequate expansion of the underexpanded stent. A metanalysis was performed for the main focuses to calculate the proportions of procedural success rates with corresponding 95% confidence intervals (CIs). Random-effects models weighted by inverse variance were used because of clinical heterogeneity. This meta-analysis included 13 studies with 354 patients. The mean age was 71.3 years (95% CI 64.9 to 73.1), and 77% (95% CI 71.2% to 82.4%) were male. The mean follow-up time was 2.6 months (95% CI 1 to 15.3). Strategy success was seen in 88.7% (95% CI 82.3 to 95.1) of patients. The mean minimal stent area was reported in 6 studies, the pre-IVL value was 3.4 mm2 (95% CI 3 to 3.8), and the post-IVL value was 6.9 mm2 (95% CI 6.5 to 7.4). The mean diameter stenosis (percentage) was reported in 7 studies, the pre-IVL value was 69.4% (95% CI 60.7 to 78.2), and the post-IVL value was 14.6% (95% CI 11.1 to 18). The rate of intraprocedural complications was 1.6% (95% CI 0.3 to 2.9). In conclusion, the "stent-through" IVL plaque modification technique is a safe tool to treat SU caused by CCP, with a high success rate and a very low incidence of complications.

Intravascular imaging in coronary stent restenosis: Prevention, characterization, and management

Despite the introduction of drug-eluting stents to combat the neointimal hyperplasia that occurred after BMS implantation, in-stent restenosis is still encountered in a significant number of patients, particularly as increasingly complex lesions are tackled by percutaneous coronary intervention. Many biological and mechanical factors interplay to produce restenosis, some of which are avoidable. Intravascular imaging provided unique insights into various forms of stent-related mechanical issues that contribute to this phenomenon. From a practical perspective, intravascular imaging can therefore help to optimize the stenting procedure to avert these issues. Moreover, once the problem of restenosis eventuates, imaging can guide the management by tackling the underlying identified mechanism. Finally, it can be used to evaluate the re-intervention results. Nevertheless, with the emergence of different treatment options, more evidence is needed to define patient/lesion-specific characteristics that may help to tailor treatment selection in a way that improves clinical outcomes.