Stent Expansion as a Mechanical Parameter to Predict Late Stent Patency

Effects of Patient Background and Treatment Strategy on Clinical Outcomes After Coronary Intervention for Calcified Nodule Lesions

Background: The presence of a calcified nodule (CN) is associated with unfavorable clinical outcomes after percutaneous coronary intervention (PCI). This study clarified the optimal management of CNs by reassessing the PCI strategy in association with patient background characteristics and clinical outcomes.

Methods and Results: Among 5,332 consecutive PCI cases managed using intra-coronary imaging, CNs were found in 167 lesions (3.1%). CNs were predominantly located at the proximal or mid-right coronary artery (RCA; 62%). More than half presented clinically as acute coronary syndrome (ACS; 56%). All-cause mortality and the target lesion revascularization (TLR) rate at 1 year were 13% and 23%, respectively. Multivariate analysis revealed that hemodialysis, diabetes, and ACS were independent risk factors for all-cause death, whereas hemodialysis and RCA location were independent risk factors for TLR. Regarding the PCI strategy, not using rotational atherectomy (RA) was significantly associated with restenosis, whereas placing a drug-eluting stent (DES) was not.

Conclusions: Both hemodialysis and RCA location were strong predictors of poor outcomes after PCI for CN. Because not using RA was significantly associated with restenosis, it may be better to use RA whenever possible.

Role of stent oversizing in patients undergoing primary percutaneous coronary intervention. An open-labeled randomized controlled trial

BACKGROUND

In patients with ST-segment-elevation myocardial infarction (STEMI), primary percutaneous coronary intervention (PPCI) is the treatment of choice. Stent undersizing might occur due to catecholamine release and coronary spasm. Although routine oversizing has been promising in several investigations, it has never been tested in randomized clinical trials. In this single-center open-label randomized clinical trial, we evaluated the role of stent oversizing in PPCI.

METHODS

Candidates for PPCI were randomly divided into oversized and non-oversized groups. In the oversized group, the stent was oversized by 10% according to the mean lumen diameter, retrieved from the quantitative coronary analysis. Primary composite endpoints were defined as the occurrence of complete total ST-segment (STR)resolution and postprocedural thrombolysis in myocardial infarction (TIMI) flow grade III.

RESULTS

The study population was comprised of 122 patients, allocated to the oversized group (N.=61) and the non-oversized group (N.=61). There was no significant difference between the 2 groups regarding the final TIMI flow grade. Complete STR was marginally more favorable in the non-oversized group (56.05±55.12 vs. 64.64±23.28; P=0.056). The troponin ratio, CK-MB ratio, and 6-month follow-up outcome - defined as target lesion revascularization, heart failure, and cardiovascular death - were comparable between the 2 groups.

CONCLUSIONS

Our study showed that routine oversizing in patients undergoing PPCI had no benefit regarding ST-segment resolution and the final TIMI flow, as well as hard cardiac events, during the follow-up.

Proximal and distal maximal luminal diameters as a guide to appropriate deployment of the ABSORB everolimus-eluting bioresorbable vascular scaffold: a sub-study of the ABSORB Cohort B and the on-going ABSORB EXTEND Single Arm Study

OBJECTIVES

Due to the limited distensibility of the everolimus-eluting bioresorbable vascular scaffold (ABSORB) compared to metallic platform stents, quantitative coronary arteriography (QCA) is a mandatory requirement for ABSORB deployment in the on-going ABSORB EXTEND Single-Arm Study. Visual assessment of vessel size in the ABSORB Cohort B study often lead to under and over-sizing of the 3 mm ABSORB in coronary vessels (recommended range of the vessel diameter ≥ 2.5 mm and ≤ 3.3 mm), with an increased risk of spontaneous incomplete scaffold apposition post ABSORB deployment. We report whether mandatory QCA assessment of vessel size pre-implantation, utilizing the maximal luminal diameter (Dmax) and established interpolated reference vessel diameter (RVD) measurements, has improved device/vessel sizing.

METHODS

Pre-implantation post-hoc QCA analyses of all 101 patients from ABSORB Cohort B (102 lesions) and first consecutive 101 patients (108 lesions) from ABSORB EXTEND were undertaken by an independent core-laboratory; all patients had a 3 mm ABSORB implanted. Comparative analyses were performed.

RESULTS

Within ABSORB Cohort B, a greater number of over-sized vessels (> 3.3 mm) were identified utilizing the Dmax compared to the interpolated RVD (17 vessels, 16.7% vs. 3 vessels, 2.9%; P = 0.002). Comparative analyses demonstrated a greater number of appropriate vessel-size selection (75 vessels, 69.4% vs. 48 vessels, 47.1%; P = 0.001), a trend towards a reduction in implantation in small (< 2.5 mm) vessels (29 vessels, 26.9% vs. 40 vessels, 39.2%; P = 0.057) and a significant decrease in the implantation in large (> 3.3 mm) vessels (4 vessels, 3.7% vs. 17 vessels, 16.7%; P = 0.002) in ABSORB EXTEND. Bland-Altman plots suggested a good agreement between operator and core-laboratory calculated Dmax measurements.

CONCLUSIONS

The introduction of mandatory Dmax measurements of vessel size prior to ABSORB implantation significantly reduced the under-sizing of the 3.0 mm scaffold in large vessels validating the use of this technique in vessel sizing prior to ABSORB implantation.

Meta-analysis of randomized studies comparing intravascular ultrasound versus angiographic guidance of percutaneous coronary intervention in pre-drug-eluting stent era

We conducted a formal meta-analysis of peer-reviewed, published, randomized studies comparing intravascular ultrasound (IVUS)-guidance and angiographic-guided bare metal stent implantation. A total of 8 studies were identified. Because the Balloon Equivalent to Stent (BEST) study was a noninferiority trial designed to compare 2 very different percutaneous coronary intervention strategies-IVUS-guided aggressive balloon angioplasty (with bail-out stenting) and angiographic-guided deliberate bare metal stent implantation-it was eliminated. An unadjusted random-effects meta-analysis was used to compare the IVUS-guided and non-IVUS-guided stenting in the 7 remaining studies. A total of 2,193 patients were randomized in 5 multicenter and 2 single-center studies. IVUS guidance was associated with a significantly larger postprocedure angiographic minimum lumen diameter. The mean difference was 0.12 mm (95% confidence interval [CI] 0.06 to 0.18, p <0.0001). IVUS guidance was also associated with a significantly lower rate of 6-month angiographic restenosis (22% vs 29%, odds ratio 0.64, 95% CI 0.42 to 0.96, p = 0.02), a significant reduction in the revascularization rate (13% vs 18%, odds ratio 0.66, 95% CI 0.48 to 0.91, p = 0.004), and overall major adverse cardiac events (19% vs. 23%, odds ratio 0.69, 95% CI 0.49 to 0.97, p = 0.03). However, no significant effect was seen for myocardial infarction (p = 0.51) or mortality (p = 0.18). In conclusion, IVUS guidance for bare metal stent implantation improved the acute procedural results (angiographic minimum lumen diameter) and thereby reduced angiographic restenosis and repeat revascularization and major adverse cardiac events, with a neutral effect on death and myocardial infarction during a follow-up period of 6 months to 2.5 years.