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Background: We investigated whether optical coherence tomography (OCT) guidance would reduce nonoptimal bioresorbable vascular scaffold (BVS) deployment. Methods: This was a randomized controlled trial. Patients who required percutaneous coronary intervention for ischemic heart disease were recruited from 2 centers in Korea. The enrolled patients were randomly assigned to receive either OCT-guided BVS (Absorb; Abbott Vascular) implantation or angiography-guided BVS implantation using an optimized technique. The primary outcome was nonoptimal deployment, which was a composite outcome of the following parameters assessed by OCT: a minimal scaffold area 2 , residual area stenosis >20%, incomplete apposition of the scaffold struts >5%, major edge dissection, or scaffold disruption. The secondary outcome was a procedural complication defined by the occurrence of no reflow, coronary perforation, or flow-limiting dissection. Results: Between September 2016 and January 2018, 88 patients (90 lesions) were assigned to OCT guidance, while 88 patients (89 lesions) were assigned to angiography guidance. The recruitment was prematurely terminated in March 2018 because the manufacturer stopped supplying BVS. Postprocedural OCT data were available for 88 lesions with OCT guidance and for 88 lesions with angiography guidance. There was nonoptimal BVS deployment postprocedurally in 35.2% of patients in the OCT-guidance group and in 38.6% in the angiography-guidance group (absolute difference, −3.7% [95% CI, −19.0% to 11.6%]; P =0.64). There were no procedural complications in either group. Conclusions: OCT-guided BVS implantation did not reduce the incidence of nonoptimal deployment compared to that of angiography-guided BVS implantation (using optimized techniques). Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02894697.

Background— Identifying predictive factors for major cardiovascular events and death in patients with unprotected left main coronary artery disease is of great clinical value for risk stratification and possible guidance for tailored preventive strategies. Methods and Results— The Interventional Research Incorporation Society-Left MAIN Revascularization registry included 5795 patients with unprotected left main coronary artery disease (percutaneous coronary intervention, n=2850; coronary-artery bypass grafting, n=2337; medication alone, n=608). We analyzed the incidence and independent predictors of major adverse cardiac and cerebrovascular events (MACCE; a composite of death, MI, stroke, or repeat revascularization) and all-cause mortality in each treatment stratum. During follow-up (median, 4.3 years), the rates of MACCE and death were substantially higher in the medical group than in the percutaneous coronary intervention and coronary-artery bypass grafting groups ( P Conclusions— Among patients with unprotected left main coronary artery disease, the key clinical predictors for MACCE and death were generally similar regardless of index treatment. This study provides effect estimates for clinically relevant predictors of long-term clinical outcomes in real-world left main coronary artery patients, providing possible guidance for tailored preventive strategies. Clinical Trial Registration— URL: https://clinicaltrials.gov . Unique identifier: NCT01341327.

For nearly half a century, coronary artery bypass grafting has been the standard treatment for patients with obstructive left main coronary artery (LMCA) disease. However, there has been considerable evolution in the field of percutaneous coronary intervention, and especially, percutaneous coronary intervention for LMCA disease has been rapidly expanded with adoption of drug-eluting stents. Some, but not all randomized trials, have shown that percutaneous coronary intervention with drug-eluting stents might be a suitable alternative for selected patients with LMCA disease instead of bypass surgery. However, none of previous trials involving early-generation drug-eluting stents was sufficiently powered and comparative trials using contemporary drug-eluting stents were limited. Recently, primary results of 2 new trials of EXCEL (Evaluation of XIENCE Everolimus Eluting Stent Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) and NOBLE (Nordic-Baltic-British Left Main Revascularization Study) were reported. However, these trials showed conflicting results, which might pose uncertainty on the optimal revascularization strategy for LMCA disease. In this article, with the incorporation of a key review on evolution of LMCA treatment, we summarize the similarity or disparity of the EXCEL and NOBLE trials, focus on how they relate to previous trials in the field, and finally speculate on how the treatment strategy may be changed or recommended for LMCA treatment.

Owing to the large area of jeopardized myocardium, left main coronary artery (LMCA) disease was associated with high morbidity and mortality and, thus, coronary artery bypass grafting has been the standard revascularization approach. However, over the several decades, there was a considerable evaluation in the field of percutaneous coronary intervention (PCI). Remarkable advancements in stent devices, technical refinement, and adjunctive medical therapy has led to improved PCI outcomes for unprotected LMCA disease.1 Especially, with a widespread use of drug-eluting stents, PCI for LMCA lesion has become technically more feasible and achieved favorable long-term clinical outcomes. Subsequently, several clinical trials using first-generation drug-eluting stents showed comparable rates of death and hard clinical end points after PCI and coronary artery bypass grafting.2–5 Recently, primary results of 2 large-sized trials adopting second-generation drug-eluting stents, EXCEL (Evaluation of XIENCE Everolimus Eluting Stent Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) and NOBLE (Nordic–Baltic–British Left Main Revascularization Study), were published.6,7 Although opposing findings may have an uncertainty on the optimal revascularization strategy, these trials also demonstrated how much PCI has been improved for LMCA treatment. See article by Andell et al Despite a marked advancement of stent device, many unresolved technical issues still remain, including how to optimize procedural results of left main intervention. For this purpose, accurate assessment of LMCA lesion is crucial …

Background— Procedural and clinical outcomes still remain unfavorable for patients with long coronary lesions who undergo percutaneous coronary intervention. The current study, therefore, evaluated 2 innovative drug-eluting stents for the management of long-lesion coronary artery disease. Methods and Results— This randomized, multicenter, prospective trial, called the Long Drug-Eluting Stent (LONG-DES) V trial, compared the biodegradable polymer–based biolimus A9–eluting stent (BES) and the durable polymer–based platinum chromium everolimus-eluting stent (PtCr-EES) in 500 patients with long (≥25 mm) coronary lesions. The primary end point of the trial was in-segment late luminal loss at the 9-month angiographic follow-up. The BES and PtCr-EES groups had similar baseline characteristics, with a slightly shorter lesion length in the BES group versus the PtCr-EES group (29.24±12.17 versus 32.27±13.84 mm; P =0.016). In-segment late luminal loss was comparable between the 2 groups at the 9-month angiographic follow-up (BES, 0.14±0.38 versus PtCr-EES, 0.11±0.37 mm; difference, 0.031; 95% confidence interval, −0.053 to 0.091; P =0.03 for a noninferiority margin of 0.11, P =0.45 for superiority), as was in-stent late luminal loss (0.20±0.41 versus 0.24±0.38 mm; P =0.29). The incidence of in-segment (6.1% versus 4.9%; P =0.63) and in-stent (3.7% versus 4.9%; P =0.59) binary restenosis was also similar between the groups. There was no significant between-group difference in the rate of composite outcome of death, myocardial infarction, and target vessel revascularization (41, 16.7% in BES versus 42, 16.5% in PtCr-EES; P =0.94). Conclusions— BES and PtCr-EES implantation showed analogous angiographic and clinical outcomes for patients with de novo long coronary lesions. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT01186120.

Background— Procedural and clinical outcomes still remain unfavorable for patients with long coronary lesions who undergo stent-based coronary interventions. Therefore, we compared the relative efficacy and safety of resolute zotarolimus-eluting stents (R-ZES) and sirolimus-eluting stents (SES) for patients with de novo long coronary lesions. Methods and Results— This randomized, multicenter, prospective trial, called the Percutaneous Treatment of LONG Native Coronary Lesions With Drug-Eluting Stent-IV (LONG-DES IV) trial, compared long R-ZES and SES in 500 patients with long (≥25 mm) native coronary lesions. The primary end point of the trial was in-segment late luminal loss at 9-month angiographic follow-up. The baseline characteristics were not different between R-ZES and SES groups, including lesion lengths (32.4±13.5 mm versus 31.0±13.5 mm, P =0.27). At 9-month angiographic follow-up, the R-ZES was noninferior to the SES with respect to in-segment late luminal loss, the primary study end point (0.14±0.38 mm versus 0.12±0.43 mm, P for noninferiority=0.03, P for superiority=0.68). In addition, in-stent late luminal loss (0.26±0.36 mm versus 0.24±0.42 mm, P =0.78) and the rates of in-segment (5.2% versus 7.2%, P =0.44) and in-stent (4.0% versus 6.0%, P =0.41) binary restenosis were not significantly different between the 2 groups. There were no significant between-group differences in the rate of adverse clinical events (death, myocardial infarction, stent thrombosis, target-lesion revascularization, and composite outcomes). Conclusions— For patients with de novo long coronary artery disease, R-ZES implantation showed noninferior angiographic outcomes as compared with SES implantation. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT01186094.

Background— As a substudy of the large, randomized ZEST (Comparison of the Efficacy and Safety of Zotarolimus-Eluting Stent with Sirolimus-Eluting and PacliTaxel-Eluting Stent for Coronary Lesions) trial comparing first- and second-generation drug-eluting stents, we evaluated intimal hyperplasia (IH) and vascular changes using volumetric intravascular ultrasound analysis. Methods and Results— Complete angiographic and volumetric intravascular ultrasound data immediately after stenting and at 9-month follow-up were available in 162 patients with 183 lesions: 61 sirolimus-eluting stents (SES), 64 paclitaxel-eluting stents (PES), and 58 zotarolimus-eluting stents (ZES). External elastic membrane, stent, lumen, and peristent plaque volumes (external elastic membrane minus stent) were normalized by stent length. Percent IH volumes were calculated as [IH volume/stent volume]×100, %. Reduction of minimal luminal area) was greater in PES than SES (−1.4±1.5 mm 2 versus −0.7±0.9 mm 2 , P =0.003), whereas minimal luminal area change in ZES was not significantly different from SES (−1.2±1.0 mm 2 versus −0.7±0.9 mm 2 , P =0.055). Percent IH volume was less in SES compared with PES (9.8±6.0% versus 17.5±11.2%, P =0.002) or with ZES (9.8±6.0% versus 18.2±7.6%, P =0.005). Comparing ZES versus PES, there were no significant differences in %IH volume (17.5±11.2% versus 18.2±7.6%, P =0.779) or changes in normalized lumen volume (−1.2±1.3 mm 2 versus −1.1±0.8 mm 2 , P =0.452). Late stent malapposition was identified in 8 (13%) SES and 2 (3%) PES but in no ZES ( P =0.050). Angiographic restenosis was detected in 6 lesions (3 PES and 3 ZES). Conclusions— The degree of neointimal growth in ZES was similar to that in PES but less than that in SES. ZES had no late stent malappositions. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00418067.

Background— We assessed optimal intravascular ultrasound (IVUS) criteria for predicting functional significance of intermediate coronary lesions. Methods and Results— Overall, 201 patients with 236 coronary lesions underwent IVUS and invasive physiological assessment before intervention. Fractional flow reserve (FFR) was measured at maximal hyperemia induced by intravenous adenosine infusion. FFR P =0.032), plaque burden (β=−0.002; 95% CI, −0.003 to 0.001; P =0.001), lesion length with a lumen area 2 (β=−0.003; 95% CI, −0.005 to −0.001; P =0.005), and left anterior descending artery location (β=−0.035; 95% CI, −0.055 to −0.016; P =0.001). The best cutoff value (with a maximal accuracy) of the MLA to predict FFR 2 , with a diagnostic accuracy of 68% (90% sensitivity, 60% specificity, and area under the curve=0.800; 95% CI, 0.742 to 0.848; P P 2 was 3.1 mm (84%sensitivity, 63%specificity, and area under the curve=0.765; 95% CI, 0.706 to 0.818; P 2 , 112 (96%) had an FFR ≥0.80,; and all but 1 showed FFR ≥0.75. Conversely, 44 (37%) lesions with an MLA 2 had an FFR Conclusions— IVUS-derived MLA ≥2.4 mm 2 may be useful to exclude FFR 2 . Thus, FFR or stress tests may be necessary to accurately identify ischemia-inducible intermediate stenoses.

Background— The long-term natural history of acquired malapposition continues to be the subject of debate. Methods and Results— Using volumetric intravascular ultrasound analyses, we evaluated serial (poststenting, 6-month, and 2-year follow-up) changes in drug-eluting stent–treated vascular segments with acquired malapposition. External elastic membrane, stent, lumen, malapposition, and peristent plaque+media (P+M=external elastic membrane −stent− malapposition) areas were measured; and volumes were calculated and divided by stent length (normalized volume). Among 250 lesions in which complete serial intravascular ultrasound data were available, stent malapposition was identified in 19 lesions (7.6%) at 6 months, and an additional 13 malapposition lesions were newly detected at 2 years (5.2%). Because no malapposition sites resolved, the malapposition rate at 2 years was 12.8%. Malapposition areas and volumes were correlated to the increases in external elastic membrane (positive remodeling) throughout the study period, from immediately after stenting to 6 months and from 6 months to 2 years, both in the group that developed malapposition at 6 months and in the group that developed malapposition at 2 years. Clinical follow-up beyond the 2 year intravascular ultrasound study was done in all patients. Overall, there were 2 cardiac deaths and 1 noncardiac death. Two patients presented with acute myocardial infarction associated with very late stent thrombosis (1 definite stent thrombosis, 1 probable stent thrombosis). Three patients underwent repeat revascularization owing to in-stent restenosis developed after the 2-year follow-up. Conclusions— Expansive vascular remodeling may play a role in the development and dynamic progression of acquired drug-eluting stent malapposition, not only during the first 6 months after implantation but thereafter.

Background— The clinical characteristics that identify high-risk subsets of patients with unprotected left main coronary artery disease undergoing percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) have not been well established. Methods and Results— Between January 2000 and June 2006, 2240 patients with unprotected left main coronary artery disease underwent PCI (n=1102) or CABG (n=1138). Twenty-six preprocedural parameters were evaluated by univariate and multivariate Cox regression analysis to identify independent predictors of all-cause mortality and target-vessel revascularization. Interaction tests were performed to compare heterogeneities of effects of preprocedural parameters depending on the revascularization methods. During follow-up (median of 3.1 years), 187 patients died (78 PCI and 109 CABG) and 149 patients had target-vessel revascularization (121 PCI and 28 CABG). EuroSCORE ≥6 was an independent predictor of death in both groups. Additional independent predictors were chronic renal failure and previous congestive heart failure in the PCI group and age ≥75 years, atrial fibrillation, right coronary artery disease, and left main distal bifurcation disease in the CABG group. Interaction analysis showed no heterogeneities of the effects of variables depending on the revascularization methods. Independent predictors of target-vessel revascularization were acute coronary syndrome and left main distal bifurcation disease in the PCI group and history of coronary intervention in the CABG group. The interaction between previous PCI and treatment remained after adjustment for all independent predictors of target-vessel revascularization (interaction P =0.0345). Conclusions— Several clinical characteristics were identified as important preprocedural predictors of long-term adverse outcomes after percutaneous or surgical revascularization in patients with unprotected left main coronary artery disease.

Background— Although intravascular ultrasound (IVUS) guidance has been useful in stenting for unprotected left main coronary artery stenosis, its impact on long-term mortality is still unclear. Methods and Results— In the MAIN-COMPARE registry, patients with unprotected left main coronary artery stenosis in a hemodynamically stable condition underwent elective stenting under the guidance of IVUS (756 patients) or conventional angiography (219 patients). Patients with acute myocardial infarction were excluded. The 3-year outcomes between the 2 groups were primarily compared using propensity-score matching in the entire and separate populations according to stent type. In 201 matched pairs of the overall population, there was a tendency of lower risk of 3-year morality with IVUS guidance compared with angiography guidance (6.0% versus 13.6%, log-rank P =0.063; hazard ratio, 0.54; 95% CI, 0.28 to 1.03; Cox-model P =0.061). In particular, in 145 matched pairs of patients receiving drug-eluting stent, the 3-year incidence of mortality was lower with IVUS guidance as compared with angiography guidance (4.7% versus 16.0%, log-rank P =0.048; hazard ratio, 0.39; 95% CI, 0.15 to 1.02; Cox model P =0.055). In contrast, the use of IVUS guidance did not reduce the risk of mortality in 47 matched pairs of patients receiving bare-metal stent (8.6% versus 10.8%, log-rank P =0.35; hazard ratio, 0.59; 95% CI, 0.18 to 1.91; Cox model P =0.38). The risk of myocardial infarction or target vessel revascularization was not associated with the use of IVUS guidance. Conclusions— Elective stenting with IVUS guidance, especially in the placement of drug-eluting stent, may reduce the long-term mortality rate for unprotected left main coronary artery stenosis when compared with conventional angiography guidance.

We appreciate Dr Layland et al for their interest, and fully agree with the concern that fractional flow reserve (FFR) may underestimate the functional significance of stenotic lesions in patients with ST-segment elevation myocardial infarction (STEMI).1,2 Increased microvascular resistance may have an influence on FFR by altering distal pressure, which is especially remarkable in the culprit lesions with slow flow. Mostly, previous observations were based on “culprits” in the setting of early after STEMI. To the contrary, our inclusion was totally different from the previous studies. Although our data included a small number of patients with …

We appreciate the article regarding the comments on our intravascular ultrasound (IVUS) substudy of the MAIN-COMPARE registry assessing the effectiveness of IVUS-guided stenting for unprotected left main coronary artery stenosis.1 Their interests and questions about our results are very useful for a changing substrate. We certainly agree with the comments on our limitations that occurred because of the nonrandomized registry study design. First, regarding the question on presenting symptom, which was …