In-Stent Restenosis of Drug-Eluting Stents Compared With a Matched Group of Patients With De Novo Coronary Artery Stenosis

Current Management of In-Stent Restenosis

In-stent restenosis (ISR) remains the primary cause of target lesion failure following percutaneous coronary intervention (PCI), resulting in 10-year incidences of target lesion revascularization at a rate of approximately 20%. The treatment of ISR is challenging due to its inherent propensity for recurrence and varying susceptibility to available strategies, influenced by a complex interplay between clinical and lesion-specific conditions. Given the multiple mechanisms contributing to the development of ISR, proper identification of the underlying substrate, especially by using intravascular imaging, becomes pivotal as it can indicate distinct therapeutic requirements. Among standalone treatments, drug-coated balloon (DCB) angioplasty and drug-eluting stent (DES) implantation have been the most effective. The main advantage of a DCB-based approach is the avoidance of an additional metallic layer, which may otherwise enhance neointimal hyperplasia, provide the substratum for developing neoatherosclerosis, and expose the patient to a persistently higher risk of coronary ischemic events. On the other hand, target vessel scaffolding by DES implantation confers relevant mechanical advantages over DCB angioplasty, generally resulting in larger luminal gain, while drug elution from the stent surface ensures the inhibition of neointimal hyperplasia. Nevertheless, repeat stenting with DES also implies an additional permanent metallic layer that may reiterate and promote the mechanisms leading to ISR. Against this background, the selection of either DCB or DES on a patient- and lesion-specific basis as well as the implementation of adjuvant treatments, including cutting/scoring balloons, intravascular lithotripsy, and rotational atherectomy, hold the potential to improve the effectiveness of ISR treatment over time. In this review, we comprehensively assessed the available evidence from randomized trials to define contemporary interventional treatment of ISR and provide insights for future directions.

Prognostic impact of in-stent restenosis in normal weight, overweight, and obese patients undergoing percutaneous coronary intervention

BACKGROUND

Among patients undergoing percutaneous coronary intervention (PCI), in-stent restenosis (ISR) is related with a worse prognosis, while higher body mass index (BMI) values are associated with better outcomes. It is unclear whether the prognostic impact of ISR varies in function of BMI.

METHODS

Patients undergoing PCI at a large center from 2012 to 2019 not presenting with an acute myocardial infarction (MI) were included. Subjects with BMI < 18.5 kg/m2 or treated with bare metal stents were excluded. Patients were stratified according to type of lesion treated (ISR vs. no-ISR) and into four BMI categories: normal weight (BMI 18.5-25 kg/m2 ), overweight (25.0-29.9 kg/m2 ), class I obesity (30.0-34.9 kg/m2 ), class II-III obesity (≥35.0 kg/m2 ). The primary outcome was major adverse cardiovascular events (MACE), a composite of all-cause death, MI, and target vessel revascularization (TVR) at 1 year.

RESULTS

Out of 16,234 patients, 3694 (23%) underwent PCI for ISR. ISR as compared to no-ISR was associated with a consistent increased risk of MACE within the normal weight (18.8% vs. 7.8%, adj. hazard ratio (HR): 1.99, 95% confidence interval [CI]: 1.51-2.64), overweight (19.1% vs. 6.4%, adj. HR: 2.35, 95% CI: 1.91-2.88), class I obesity (18.3% vs. 6.8%, adj. HR: 1.95, 95% CI: 1.47-2.57), and class II-III obesity (16.4% vs. 7.4%, adj. HR: 1.61, 95% CI: 1.09-2.37) groups (interaction p-value: 0.192). The ISR-related risks were mostly driven by an excess of TVR.

CONCLUSIONS

At 1 year, ISR was associated with an increased risk of MACE irrespective of BMI, mostly due to an excess of TVR after ISR.

Drug-coated balloon: an effective alternative to stent strategy in small-vessel coronary artery disease-a meta-analysis

Background

Small-vessel coronary artery disease (CAD) is frequently observed in coronary angiography and linked to a higher risk of lesion failure and restenosis. Currently, treatment of small vessels is not standardized while having drug-eluting stents (DES) or drug-coated balloons (DCBs) as possible strategies. We aimed to conduct a meta-analytic approach to assess the effectiveness of treatment strategies and outcomes for small-vessel CAD.

Methods

Comprehensive literature search was conducted using PubMed, Embase, MEDLINE, and Cochrane Library databases to identify studies reporting treatment strategies of small-vessel CAD with a reference diameter of ≤3.0 mm. Target lesion revascularization (TLR), target lesion thrombosis, all-cause death, myocardial infarction (MI), and major adverse cardiac events (MACE) were defined as clinical outcomes. Outcomes from single-arm and randomized studies based on measures by means of their corresponding 95% confidence intervals (CI) were compared using a meta-analytic approach. Statistical significance was assumed if CIs did not overlap.

Results

Thirty-seven eligible studies with a total of 31,835 patients with small-vessel CAD were included in the present analysis. Among those, 28,147 patients were treated with DES (24 studies) and 3,299 patients with DCB (18 studies). Common baseline characteristics were equally distributed in the different studies. TLR rate was 4% in both treatment strategies [0.04; 95% CI 0.03-0.05 (DES) vs. 0.03-0.07 (DCB)]. MI occurred in 3% of patients receiving DES and in 2% treated with DCB [0.03 (0.02-0.04) vs. 0.02 (0.01-0.03)]. All-cause mortality was 3% in the DES group [0.03 (0.02-0.05)] compared with 1% in the DCB group [0.01 (0.00-0.03)]. Approximately 9% of patients with DES developed MACE vs. 4% of patients with DCB [0.09 (0.07-0.10) vs. 0.04 (0.02-0.08)]. Meta-regression analysis did not show a significant impact of reference vessel diameter on outcomes.

Conclusion

This large meta-analytic approach demonstrates similar clinical and angiographic results between treatment strategies with DES and DCB in small-vessel CAD. Therefore, DES may be waived in small coronary arteries when PCI is performed with DCB.

Right-Sided Minimally Invasive Direct Coronary Artery Bypass: Clinical Experience and Perspectives

Objective: Minimally invasive direct coronary artery bypass grafting (MIDCAB) using the left internal thoracic artery to the left descending artery is a clinical routine in the treatment of coronary artery disease. Far less is known on right-sided MIDCAB (r-MIDCAB) using the right internal thoracic artery (RITA) to the right coronary artery (RCA). We aimed to present our experience in patients with complex coronary artery disease who underwent r-MIDCAB. Materials and Methods: Between October 2019 and January 2023, 11 patients received r-MIDCAB using RITA to RCA bypass in a minimally invasive technique via right anterior minithoracotomy without using a cardiopulmonary bypass. Underlying coronary disease was complex right coronary artery stenosis (n = 7) and anomalous right coronary artery (ARCA; n = 4). All procedure-related and outcome data were evaluated prospectively. Results: Successful minimally invasive revascularization was achieved in all patients (n = 11). There were no conversions to sternotomy and no re-explorations for bleeding. Furthermore, no myocardial infarction, no strokes, and, most importantly, no deaths were observed. During the follow-up period (median 24 months), all patients were alive and 90% were completely angina free. Two patients received a repeated revascularization after surgery but independently from the RITA-RCA bypass, which was fully competent in both patients. Conclusion: Right-sided MIDCAB can be performed safely and effectively in patients with expected technically challenging percutaneous coronary intervention of the RCA and in patients with ARCA. Mid-term results showed high freedom from angina in nearly all patients. Further studies with larger patient cohorts and more evidence are needed to provide the best revascularization strategy for patients suffering from isolated complex RCA stenosis and ARCA.

Stent Thrombosis and Restenosis with Contemporary Drug-Eluting Stents: Predictors and Current Evidence

Iterations in stent technologies, advances in pharmacotherapy, and awareness of the implications of implantation techniques have markedly reduced the risk of stent failure, both in the form of stent thrombosis (ST) and in-stent restenosis (ISR). However, given the number of percutaneous coronary interventions (PCI) performed worldwide every year, ST and ISR, albeit occurring at a fairly low rate, represent a public health problem even with contemporary DES platforms. The understanding of mechanisms and risk factors for these two PCI complications has been of fundamental importance for the parallel evolution of stent technologies. Risk factors associated with ST and ISR are usually divided into patient-, lesion-, device- and procedure-related. A number of studies have shown how certain risk factors are related to early (1 month) versus late/very late ST (between 1 month and 1 year and >1 year, respectively). However, more research is required to conclusively show the role of time-dependence of risk factors also in the incidence of ISR (early [1 year] or late [>1 year]). A thorough risk assessment is required due to the complex etiology of ST and ISR. The most effective strategy to treat ST and ISR is still to prevent them; hence, it is crucial to identify patient-, lesion-, device- and procedure-related predictors.

Serum glycated albumin is associated with in-stent restenosis in patients with acute coronary syndrome after percutaneous coronary intervention with drug-eluting stents: An observational study

Background

Previous studies have confirmed the predicted value of serum glycated albumin (GA) in atherosclerotic cardiovascular disease. However, the relationship between GA and the development of in-stent restenosis (ISR) after drug-eluting stent (DES) implantation has not been verified in patients with acute coronary syndrome (ACS).

Materials and methods

In this study, 797 patients diagnosed with ACS who underwent re-coronary angiography more than 6 months after the first successful DES-based percutaneous coronary intervention (PCI) were eventually included. Patients were categorized into two groups based on the median GA levels of 14.94%. Moreover, multivariate logistic regression analysis models and the net reclassification improvement and integrated differentiation improvement risk models were constructed to assess the relationship between the GA and DES-ISR in patients with ACS.

Results

The GA was significantly associated with an increased risk of DES-ISR, upon adjusting for confounding factors (as nominal variate: OR 1.868, 95% CI 1.191-2.932, P = 0.007; as continuous variate: OR 1.109, 95% CI 1.040-1.183, P = 0.002). The addition of GA to a baseline risk model had an incremental effect on the predictive value for DES-ISR (AUC: GA vs. baseline model, 0.714 vs. 0.692, comparison P = 0.017; category-free net reclassification improvement (NRI) 0.080, P = 0.035; integrated discrimination improvement (IDI) 0.023, P < 0.001).

Conclusion

GA level was significantly associated with a high risk of DES-ISR in patients with ACS treated with PCI. Moreover, the addition of the GA to a baseline risk model has an incremental effect on the predictive potential for DES-ISR.

Drug-Coated Balloon-Only Angioplasty Outcomes in Diabetic and Nondiabetic Patients with De Novo Small Coronary Vessels Disease

Background

The revascularization of small vessels using drug-eluting stents remains challenging. The use of the drug-coated balloon is an attractive therapeutic strategy in de novo lesions in small coronary vessels, particularly in the diabetic group. This study aimed to assess the outcomes of DCB-only angioplasty in small vessel disease.

Methods

A total of 1198 patients with small vessel disease treated with DCB-only strategy were followed. Patients were divided into the diabetic and nondiabetic groups. Clinical and angiographical follow-up were organized at 12 months. The primary endpoints were target lesion failure and secondary major adverse cardiac events.

Results

There was a significantly higher rate of target lesion failure among diabetic patients compared to nondiabetic [17 (3.9%) vs. 11 (1.4%), P=0.006], taken separately, the rate of target lesion revascularization significantly differed between groups with a higher rate observed in the diabetic group [9 (2%) vs. 4 (0.5%), P=0.014]. Diabetes mellitus remained an independent predictor for TLF (HR: 2.712, CI: 1.254–5.864, P=0.011) and target lesion revascularization (HR: 3.698, CI: 1.112–12.298, P=0.033) after adjustment. However, no significant differences were observed between groups regarding the target vessel myocardial infarction (0.6% vs. 0.1%, P=0.110) and MACE [19 (4.4%) vs. 21 (2.7%), P=0.120].

Conclusion

Drug-coated balloon-only treatment achieved lower incidence rates of TLF and MACE. Diabetes is an independent predictor for target lesion failure and target lesion revascularization at one year following DCB treatment in small coronary vessels. We observed no significant differences between groups regarding MACE in one year.

Coronary In-Stent Restenosis–Predictors and Treatment

BACKGROUND

Despite the use of modern drug-eluting stents (DES), in-stent restenosis (ISR) may still occur in as many as 2-10% of percutaneous coronary interventions (PCI) in certain lesion/patient subsets. ISR causes increased morbidity after stent implantation; acute myocardial infarction is a frequent correlate to a clinical ISR, arising in 5-10% of cases. Compared to de novo stenosis, patients with ISR also present more frequently with symptoms of unstable angina pectoris (45% versus 61%). In this article, we discuss the risk factors for ISR and the corresponding diagnostic measures and effective treatment strategies.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, with special attention to current international guidelines and specialist society recommendations.

RESULTS

The type of implanted stent, the presence of diabetes mellitus, previous bypass surgery, and small vessel caliber are predictors for ISR. In their guidelines, the European specialist societies (ESC/EACTS) recommend repeated PCI with DES implantation or drug-coated balloon (DCB) angioplasty as the methods of choice for the treatment of ISR. This approach is supported by evidence from meta-analyses. The RIBS-IV trial showed that revascularization treatment of the target lesion is needed less often after everolimus-eluting stent (EES) implantation than after DCB dilatation (11 [7.1%] versus 24 [15.6%]; p = 0.015; hazard ratio: 0.43; 95% confidence interval: [0.21; 0.87]).

CONCLUSION

Because the pathogenesis of ISR is multifactorial, differentiated risk stratification is necessary. The identification of patient-, stent-, and lesion-related predictors is particularly important, as the most effective way to combat ISR is to prevent it.

Impact of intravascular ultrasound on Outcomes following PErcutaneous coronary interventioN for In-stent Restenosis (iOPEN-ISR study)

BACKGROUND

Percutaneous coronary intervention (PCI) for in-stent restenosis (ISR) remains common. Intravascular imaging allows for the determination of the mechanism of ISR, potentially guiding appropriate therapy. Intravascular ultrasound (IVUS)-guided stent implantation is associated with a reduction in adverse events after PCI, but its impact on treatment of ISR is not clear.

METHODS

All patients with 1-year follow-up after ISR treatment from 2003 through 2016 were included and stratified by IVUS use. The primary endpoint was the rate of major adverse cardiac events (MACE) at 1 year, defined as the composite of all-cause mortality, Q-wave myocardial infarction, and target vessel revascularization (TVR).

RESULTS

The final analysis included 1522 ISR patients, 65.9% of whom were treated with IVUS guidance. The primary endpoint occurred in 18.0% of patients treated with IVUS guidance vs. 24.5% of patients treated with angiography guidance (p = 0.0014). Post-dilatation was used more often with IVUS (18.6% vs. 14.1%, p < 0.001), with a larger diameter of new stents (3.04 ± 0.35 mm vs. 2.94 ± 0.47 mm, p = 0.001). At 1 year, TVR occurred in 14.5% with IVUS guidance and 19.2% with angiography guidance (p = 0.021).

CONCLUSIONS

The use of IVUS is associated with decreased MACE at 1 year following PCI for ISR. These results support routine IVUS for the treatment of ISR lesions.

Long-term outcomes of percutaneous coronary intervention for in-stent restenosis among Medicare beneficiaries

BACKGROUND

In-stent restenosis (ISR) is highly prevalent and leads to repeat revascularisation. Long-term implications of ISR are poorly understood.

AIMS

This study aimed to evaluate the long-term outcomes of patients undergoing percutaneous coronary intervention (PCI) for ISR.

METHODS

National Cardiovascular Data Registry CathPCI records for individuals aged ≥65 years undergoing PCI from July 2009 to December 2014 were linked to Medicare claims. Baseline characteristics and long-term rates of death, myocardial infarction (MI), repeat revascularisation including target vessel revascularisation (TVR), and major adverse cardiovascular and cerebrovascular events (MACCE) were compared between ISR PCI versus de novo lesion PCI.

RESULTS

Of 653,304 individuals, 10.2% underwent ISR PCI and 89.8% underwent de novo lesion PCI. The median duration of follow-up was 825 days (quartile 1: 352 days-quartile 3: 1,379 days). The frequency of MACCE (55.6% vs 45.0%; p<0.001), all-cause mortality (27.8% vs 25.5%; p<0.001), MI (19.0% vs 12.3%; p<0.001), repeat revascularisation (31.9% vs 18.6%; p<0.001), TVR (22.4% vs 8.0%; p<0.001), and stroke (8.8% vs 8.3%; p=0.005) was higher after ISR PCI. After multivariable adjustment, ISR PCI remained associated with worse long-term outcomes than after de novo lesion PCI (hazard ratio [HR] for MACCE 1.24 [95% CI: 1.22, 1.26], mortality 1.07 [95% CI: 1.05, 1.09], MI 1.44 [95% CI: 1.40, 1.48], repeat revascularisation 1.55 [95% CI: 1.51, 1.59], and TVR 2.50 [95% CI: 2.42, 2.58]).

CONCLUSIONS

ISR PCI was common and was associated with a significantly higher risk of recurrent long-term major ischaemic events compared to patients undergoing de novo lesion PCI. There remains a need for new strategies to minimise ISR.

One-Year Outcomes After Treatment of Ostial In-Stent Restenosis in Left Circumflex Versus Left Anterior Descending or Right Coronary Artery

The prognosis of left circumflex (LC) versus non-LC in-stent restenosis (ISR) ostial lesions following treatment has not been assessed. We aimed to assess this prognosis. Anecdotally, treatment of ostial LC ISR has been associated with high recurrence rates. We performed a retrospective analysis of patients from our institution who underwent coronary intervention of an ostial ISR lesion between 2003 and 2018. The primary endpoint was target lesion revascularization (TLR) and major adverse cardiovascular events (MACE). Overall, 563 patients underwent ostial ISR lesion intervention, 144 for an ostial LC ISR lesion. Compared to patients with ostial ISR in non-LC lesions, patients with ostial LC ISR were older, had higher rates of diabetes mellitus and previous coronary bypass surgery. At 1-year follow-up, TLR-MACE rates were 26.6% in the LC group versus 18.4% in the non-LC group (p = 0.036). The TLR rate was also higher in the LC group compared to the non-LC group (p = 0.0498). Univariate and multivariate analyses demonstrated a higher TLR-MACE rate for LC versus non-LC ostial ISR lesions. In conclusion, our study shows increased event rates after treatment of LC versus non-LC ISR lesions. Further studies should be done to assess the optimal treatment approach for ostial LC ISR.

Comparison of clinical outcomes between percutaneous coronary intervention for de novo lesions versus in-stent restenosis lesions

In-stent restenosis (ISR) remains the primary concern after a percutaneous coronary intervention (PCI) and is considered to be associated with worse clinical outcomes. However, comparative data on ISR and de novo lesions are rare. Therefore, we aimed to compare PCI-related clinical outcomes between patients with de novo lesions and those with ISR lesions. We undertook a retrospective analysis of patients who had undergone a PCI between 2013 and 2020. The incidences of major adverse cardiac and cerebrovascular events (MACCE) and all-cause death over a 2-year follow-up period were evaluated. In total, 1538 patients were enrolled and divided into two groups: a de novo lesions group (n = 1258, 81.8%) and an ISR lesions group (n = 280, 18.2%). Patients in the ISR lesions group were significantly older, with a higher prevalence of hypertension, diabetes mellitus, dyslipidemia, and chronic kidney disease than those in the de novo lesions group. Kaplan-Meier curves showed no significant between-group differences in the incidence of MACCE (log-rank, p = 0.93) and all-cause death (p = 0.09). After adjustment for other covariates, PCIs for ISR lesions were not found to be significantly associated with MACCE (hazard ratio [HR], 1.10; 95% confidential interval [CI] 0.49-2.49; p = 0.81) and all-cause death (HR, 0.58; 95% CI 0.26-1.31; p = 0.19). PCIs for ISR lesions were not associated with worse clinical outcomes compared with PCIs for de novo lesions.

Drug-Coated balloons vs drug-eluting stents for the treatment of small coronary artery disease: A meta-analysis of randomized trials

OBJECTIVES AND BACKGROUND

There is conflicting evidence about the effects of drug-coated balloons (DCB) compared with drug-eluting stents (DES) in patients with native small vessel coronary artery disease (CAD).

METHODS

The PubMed, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases and main international conference proceedings were searched for randomized controlled trials (RCT) comparing DCB versus DES in patients with native small vessel CAD. Data were pooled by meta-analysis using a random-effects model. The primary endpoint was target vessel revascularization (TVR). Secondary clinical endpoints were: myocardial infarction (MI), target lesion revascularization (TLR), all-cause death, cardiac death, and stent thrombosis or target vessel thrombosis. Secondary angiographic outcomes were: in-segment restenosis, in-segment percentage-diameter stenosis, in-segment late lumen loss, in-segment net luminal gain, and in-segment minimal lumen diameter.

RESULTS

Five trials enrolling 1,459 patients were included. Mean clinical follow-up was 10.2 months. The use of DCB, compared with DES, was associated with similar risk of TVR (odds ratio [OR]: 0.97; 95% confidence interval [CI] 0.56 to 1.68; p = .92), TLR (OR: 1.74; 95% CI: 0.57 to 5.28; p = .33), all-cause death (OR: 1.03; 95% CI: 0.14 to 7.48; p = .98), with a trend toward a lower risk of MI (OR: 0.49; 95% CI: 0.23 to 1.03; p = .06), and with significant lower risk of vessel thrombosis (OR: 0.12; 95% CI: 0.01 to 0.94; p = .04). DCB use was associated with similar risk of angiographic restenosis (OR: 1.12; 95% CI 0.69 to 1.84; p = .64), comparable late luminal loss (standardized mean difference (SMD): -0.18; 95% CI: -0.39 to 0.03; p = .09), while leading to significant higher percentage diameter stenosis (SMD: 0.27; 95% CI 0.12 to 0.41; p < .01) and smaller minimal luminal diameter (SMD: -0.52; 95% CI: -0.86 to -0.18; p = .003).

CONCLUSION

Compared with DES, the use of DCB for the treatment of native small vessel CAD is associated with similar TVR and restenosis and reduces the risk of vessel thrombosis, although DES implantation yields slightly better angiographic surrogate endpoints.