Short and long-term safety and efficacy of polymer-free vs. durable polymer drug-eluting stents. A comprehensive meta-analysis of randomized trials including 6178 patients

Background

The efficacy and safety of polymer-free drug-eluting stents (DESs) in clinical practice is currently subject of debate; randomized trials (RCTs) conducted so far provided conflicting results or were underpowered to definitively address this question; we aimed to investigate the efficacy and safety profile of polymer-free vs. durable polymer DES by a comprehensive meta-analysis of RCTs.

Methods

MEDLINE, Google Scholar, EMBASE and Cochrane databases were searched for RCTs comparing polymer-free to durable polymer DES. Safety endpoints at short-term (≤1 year) and long-term follow-up (>1-year) were: death, myocardial infarction (MI) and stent thrombosis (ST); main efficacy endpoints were: target lesion revascularization (TLR) and target vessel revascularization (TVR).

Results

Eight RCTs including 6178 patients were included. No significant differences in mortality were observed between polymer-free and durable polymer DESs at both short- and long-follow up (OR [95% CI] = 0.79 [0.58–1.08], p = 0.14; and 0.80 [0.58–1.10], p = 0.17 respectively); polymer free and durable polymer DESs provided comparable short and long-term MI rates; at short-term: OR [95% CI] = 1.13 [0.83–1.54], p = 0.44 and at long-term: OR [95% CI] = 1.27 [0.87–1.85], p = 0.22. Similarly, these two different devices proved equally effective in regards to ST, TLR and TVR over the short and long follow-up period.

Conclusions

Polymer-free DESs are as safe and effective as durable polymer DES; however, there is no evidence of any additional benefits provided by this new technology.     

Clinical outcomes with 6 months dual antiplatelet therapy after implantation of Biolimus-A9 drug eluting coronary stents

Introduction

Duration of dual antiplatelet therapy (DAPT) following drug eluting stent (DES) implantation remains poorly defined. Endothelialisation of biodegradable polymer biolimus-eluting stents occurs early, and 6 months DAPT may be adequate.

Aims

We evaluated long term outcome in patients treated with biolimus-eluting stents who were treated with 6 months DAPT. Endpoints included cardiac death and non-fatal stent thrombosis occurring 6 to 12 months after stent implantation.

Methods

692 patients (77.2% male), aged 65.6 ± 12.5 years received biolimus-eluting DES (March 2008 –November 2011). Vital status was tracked through the Medical Research Information Service. Episodes of non-fatal stent thrombosis, (Academic Research Consortium definition) between months 6 and 12 were tracked via systematic database searches (5 PCI centres).

Results

Presentations included acute coronary syndrome (47.2%) and stable coronary disease (52.8%). Vessels treated included left main stem (6.8%), left anterior descending (37.4%), circumflex (19.1%), right coronary artery (34.5%) and saphenous vein graft (2.1%) respectively. High-risk subsets included diabetes (15.6%); AHA type C lesions (35.1%) and chronic total occlusions (12.8%). During median follow-up of 700 days (0 to 1392) there were 42 deaths (6.1%); 4.2% at 0–6 months, 1.0% at 6–12 months and 0.9% at > 12 months. Of the 7 deaths between 6 and 12 months, one death was adjudicated as possible stent thrombosis. There were no cases of non-fatal known stent thrombosis. All cause mortality accrued with smooth decremental incidence. Statistical examination showed no evidence of event clustering between 6 and 12 months.

Conclusions

After implantation of biodegradable polymer biolimus-eluting coronary stents, 6 months DAPT appears to be adequate, safe and effective.     

Long-term coronary arterial response to biodegradable polymer biolimus-eluting stents in comparison with durable polymer sirolimus-eluting stents and bare-metal stents: Five-year follow-up optical coherence tomography study

Objective

The long-term coronary arterial response of biodegradable polymer biolimus-eluting stents (BES) remains unclear. We sought to evaluate the coronary arterial response of biodegradable polymer BES at 5 years after stent implantation using optical coherence tomography (OCT) as compared with that of durable polymer sirolimus-eluting stents (SES) and bare-metal stents (BMS).

Methods

Five-year follow-up OCT was performed in 30 patients with 33 stents (10 with 12 BES; 10 with 11 SES; 10 with 10 BMS). Quantitative parameters and qualitative characteristics of the neointima were evaluated. A total of 5178 struts (BES, n = 2056; SES, n = 1410; BMS, n = 1712) were analyzed.

Results

Uncovered struts were found in 15 out of 2055 struts in the BES (weighted estimate 0.01%, 95% confidence intervals [CI]: 0.00–0.33%) and 54 out of 1410 struts in the SES (0.11%, 95% CI: 0.00–3.33%) (odds ratio [OR] 0.12, 95% CI: 0.01–1.95, p = 0.13). None of 1712 struts were uncovered in the BMS. Cross-sectional qualitative analysis of neointimal tissue showed that the frequency of lipid-laden neointima tended to be lower in the BES (2.26%, 95% CI: 0.38–12.3%) compared with the SES (9.90%, 95% CI: 4.37–20.9%; OR 0.21, 95% CI 0.03–1.16, p = 0.07), and was similar to the BMS (2.23%, 95% CI: 0.54–8.74%; OR 0.98, 95% CI 0.13–7.14, p = 0.98).

Conclusions

Biodegradable polymer BES shows a favorable coronary arterial response compared with SES, but different response with BMS at 5 years follow-up. The observed frequency of in-stent neoatherosclerosis within BES was similar to BMS and tended to be lower than SES.     

Intravascular ultrasound assessed incomplete stent apposition and stent fracture in stent thrombosis after bare metal versus drug-eluting stent treatment the Nordic Intravascular Ultrasound Study (NIVUS)

Background

This prospective multicenter registry used intravascular ultrasound (IVUS) in patients with definite stent thrombosis (ST) to compare rates of incomplete stent apposition (ISA), stent fracture and stent expansion in patients treated with drug-eluting (DES) versus bare metal (BMS) stents. ST is a rare, but potential life threatening event after coronary stent implantation. The etiology seems to be multifactorial.

Methods

124 patients with definite ST were assessed by IVUS during the acute ST event. The study was conducted in 15 high-volume percutaneous coronary intervention -centers in the Nordic–Baltic countries.

Results

In early or late ST there were no differences in ISA between DES and BMS. In very late ST, ISA was a more frequent finding in DES than in BMS (52% vs.16%; p = 0.005) and the maximum ISA area was larger in DES compared to BMS (1.1 ± 2.3 mm² vs. 0.1 ± 0.5 mm²; p = 0.004). Further, ISA was more prevalent in sirolimus-eluting than in paclitaxel-eluting stents (58% vs. 37%; p = 0.02). Stent fractures were found both in DES (16%) and BMS (24%); p = 0.28, and not related to time of stent thrombosis occurrence. For stents with nominal diameters ≥ 2.75 mm, 38% of the DES and 22% of the BMS had a minimum stent area of less than 5 mm²; p = 0.14.

Conclusions

Very late stent thrombosis was more prevalent and associated with more extensive ISA in DES than in BMS treated patients. Stent fracture was a common finding in ST after DES and BMS implantation.     

Comparison of frequency and severity of longitudinal stent deformation among various drug-eluting stents: An intravascular ultrasound study

Background

Longitudinal stent deformation (LSD) in drug-eluting stents (DES) has been described as a disruption of stent structure. This study aimed to compare first- versus second-generation DES with respect to their actual stent length post deployment.

Methods

A total of 617 DES for de novo coronary lesions in 552 patients were analyzed. Intravascular ultrasound (IVUS) was utilized to compare the degree and rate of LSD among six different DES types. IVUS-measured stent length was compared to the labeled length for calculation of absolute difference in stent length and relative absolute difference (absolute difference divided by the labeled length).

Results

The baseline characteristics were comparable between groups, except for higher calcification in the sirolimus-eluting stent (SES) group (p = 0.037). The absolute and relative difference in length showed the lowest degree in the SES group and the highest degree in the Endeavor zotarolimus-eluting stent group (p = 0.085 and 0.078, respectively). The percentage of more than 5% relative absolute difference was the lowest in the SES group compared to the other groups (p = 0.018). However, the percentage of significant (> 15%) relative absolute difference was similar among groups (p = 0.99). In multivariate linear regression analysis, labeled stent length and stent diameter, but not stent type, were identified as independent correlates to the absolute and relative difference in the actual stent length post-deployment.

Conclusion

This IVUS analysis confirms that among second-generation DES, there is overall similar frequency and severity of LSD when deploying in common coronary lesions.     

Relation between poststenting peristent plaque components and late stent malapposition after drug-eluting stent implantation: Virtual histology-intravascular ultrasound analysis

Background

Impact of plaque composition on late stent malapposition (LSM) after drug-eluting stent (DES) implantation has not been evaluated.

Methods

We evaluated the relation between plaque components at poststenting peristent area (between external elastic membrane and stent areas) and LSM after DES implantation in 266 patients (314 native lesions; paclitaxel-eluting stent in 205 lesions, sirolimus-eluting stent in 66 lesions, zotarolimus-eluting stent in 32 lesions and everolimus-eluting stent in 11 lesions) in whom virtual-histology intravascular ultrasound was performed at index (poststenting) and follow-up (mean: 11.7 ± 4.8 months).

Results

LSM occurred in 24 patients with 30 lesions (9.6%) and there were no significant differences in the incidences of LSM among 4 DES groups [21/205 (10.2%) in paclitaxel-eluting stent, 6/66 (9.1%) in sirolimus-eluting stent, 2/32 (6.3%) in zotarolimus-eluting stent and 1/11 (9.1%) in everolimus-eluting stent, p = 0.5)]. Patients with LSM were presented with more acute myocardial infarction (50% vs. 28%, p = 0.026) and were more diabetics (50% vs. 30%, p = 0.030) compared with those without LSM. Lesions with LSM had more poststenting peristent %necrotic core (NC) volume compared with those without LSM (25.8 ± 11.1% vs. 21.0 ± 5.7%, p < 0.001). Independent predictors of LSM were poststenting peristent %NC volume [odds ratio (OR); 1.216, 95% CI; 1.053–1.405, p = 0.008], acute myocardial infarction (OR; 2.897, 95% CI; 1.675–4.118, p = 0.029), and diabetes mellitus (OR; 2.413, 95% CI; 1.543–3.996, p = 0.038).

Conclusions

Poststenting peristent NC component especially in patients with acute myocardial infarction and in those with diabetes mellitus is associated with the development of LSM after DES implantation.     

Proximal coronary artery intervention: Stent thrombosis,restenosis and death

Background

Percutaneous coronary intervention (PCI) of lesions in the proximal left anterior descending coronary artery (LAD) may confer a worse prognosis compared with the proximal right coronary artery (RCA) and left circumflex coronary artery (LCX).

Methods

From May 2005, to May 2011 we identified all PCIs for proximal, one-vessel coronary artery disease in the Swedish Coronary Angiography and Angioplasty Registry (SCAAR). We evaluated restenosis, stent thrombosis (ST) and mortality in the LAD as compared to the RCA and LCX according to stent type, bare metal (BMS) or drug-eluting stents (DES).

Results

7840 single vessel proximal PCI procedures were identified. Mean follow-up time was 792 days. No differences in restenosis or ST were seen between the LAD and the RCA. The frequency of restenosis and ST was higher in the proximal LAD compared to the proximal LCX (restenosis: hazard ratio (HR) 2.28, confidence interval (CI) 1.56–3.34 p < 0.001; ST: HR 2.32, CI 1.11–4.85 p = 0.024). We found no difference in mortality related to coronary artery. In the proximal LAD, DES implantation was associated with a lower restenosis rate (HR 0.39, CI 0.27–0.55 p < 0.001) and mortality (HR 0.58, CI 0.41–0.82 p = 0.002) compared with BMS. In the proximal RCA and LCX, DES use was not associated with lower frequency of clinical restenosis or mortality.

Conclusions

Following proximal coronary artery intervention restenosis was more frequent in the LAD than in the LCX. Solely in the proximal LAD we found DES use to be associated with a lower risk of restenosis and death weighted against BMS.     

Clinical outcomes of patients treated with Nobori biolimus-eluting stent: Meta-analysis of randomized trials

Backgrounds

The Nobori is a new-generation, biodegradable-polymer coated, biolimus-eluting stent (BES) that has recently been investigated in several randomized trials with inconsistent results. The aim of this study was to assess the efficacy and safety of Nobori BES versus other drug-eluting stents (DES) in patients treated with percutaneous coronary intervention (PCI).

Methods

We undertook a meta-analysis of randomized trials investigating Nobori BES versus other DES. Primary efficacy and safety outcomes were target lesion revascularization (TLR) and definite/probable stent thrombosis (ST), respectively. Secondary outcomes were the composite of cardiac death/myocardial infarction (MI)/target vessel revascularization (TVR), MI and death.

Results

A total of 9114 PCI-patients randomly received Nobori BES (n = 5080) or other DES (n = 4034). This latter group comprised patients receiving everolimus- (n = 2533), sirolimus- (n = 1376) or paclitaxel-eluting stents (n = 125). Median follow-up was 11 months [interquartile range 9–12]. The Nobori BES versus other DES showed comparable risk of TLR (odds ratio [95% confidence interval] = 0.91 [0.57–1.46], p = 0.71). There was significant heterogeneity across trials due to significant lower TLR risk with Nobori BES versus paclitaxel-eluting stent (0.32 [0.10–0.98], p = 0.046; p for interaction = 0.009). Nobori BES versus other DES showed comparable risk of definite/probable ST (1.40 [0.66–2.97], p = 0.39), cardiac death/MI/TVR (1.05 [0.88–1.25], p = 0.59), MI (1.13 [0.87–1.48], p = 0.37) and death (1.09 [0.81–1.48], p = 0.56).

Conclusions

Nobori BES has comparable efficacy with other limus-eluting stents at 1-year follow-up. There is no difference in terms of safety profile between these stent platforms.     

Long-term outcomes of patients receiving zotarolimus-eluting stents in ST elevation myocardial infarction,non-ST elevation acute coronary syndrome,and stable angina: Data from the Resolute program

Background

Outcome data are limited in patients with ST-segment elevation acute myocardial infarction (STEMI) or other acute coronary syndromes (ACSs) who receive a drug-eluting stent (DES). Data suggest that first generation DES is associated with an increased risk of stent thrombosis when used in STEMI. Whether this observation persists with newer generation DES is unknown. The study objective was to analyze the two-year safety and effectiveness of Resolute™ zotarolimus-eluting stents (R-ZESs) implanted for STEMI, ACS without ST segment elevation (non-STEACS), and stable angina (SA).

Methods

Data from the Resolute program (Resolute All Comers and Resolute International) were pooled and patients with R-ZES implantation were categorized by indication: STEMI (n = 335), non-STEACS (n = 1416), and SA (n = 1260).

Results

Mean age was 59.8 ± 11.3 years (STEMI), 63.8 ± 11.6 (non-STEACS), and 64.9 ± 10.1 (SA). Fewer STEMI patients had diabetes (19.1% vs. 28.5% vs. 29.2%; P < 0.001), prior MI (11.3% vs. 27.2% vs. 29.4%; P < 0.001), or previous revascularization (11.3% vs. 27.9% vs. 37.6%; P < 0.001). Two-year definite/probable stent thrombosis occurred in 2.4% (STEMI), 1.2% (non-STEACS) and 1.1% (SA) of patients with late/very late stent thrombosis (days 31–720) rates of 0.6% (STEMI and non-STEACS) and 0.4% (SA) (P = NS). The two-year mortality rate was 2.1% (STEMI), 4.8% (non-STEACS) and 3.7% (SA) (P = NS). Death or target vessel re-infarction occurred in 3.9% (STEMI), 8.7% (non-STEACS) and 7.3% (SA) (P = 0.012).

Conclusion

R-ZES in STEMI and in other clinical presentations is effective and safe. Long term outcomes are favorable with an extremely rare incidence of late and very late stent thrombosis following R-ZES implantation across indications.     

Safety and efficacy of degradable vs. permanent polymer drug-eluting stents: A meta-analysis of 18,395 patients from randomized trials

Background

Degradable polymer drug-eluting stents (DP-DES) represent a promising strategy to improve the delayed healing and hypersensitive reaction in the vessel. However, the efficacy and safety of DP-DES vs. permanent polymer drug-eluting stents (PP-DES) are less well defined. The aim of this meta-analysis was to compare the total, short (< 30 days), mid (30 days–1 year) and long (> 1 year) term outcomes of DP-DES vs. PP-DES.

Methods

PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for randomized clinical trials to compare any of approved DP- and PP-DES. Efficacy endpoints were target-lesion revascularization (TLR) and in-stent late loss (ISLL). Safety endpoints were death, myocardial infarction (MI), and composite of definite and probable stent thrombosis (ST).

Results

The meta-analysis included 19 RCTs (n = 18,395) with interesting results. As compared with DES, there was a significantly reduced very late ST (OR [95% CI] = 0.42 [0.24–0.77], p = 0.852) and ISLL (OR [95% CI] = − 0.07 [− 0.12–0.02], p = 0.000) in DP-DES patients. However, there were no differences between DP-DES and PP-DES for other safety and efficiency outcomes, except that the stratified analysis showed a significant decreased TLR with DP-DES as compared to paclitaxel-eluting stent (OR [95% CI] = 0.41 [0.20–0.81], p = 0.457).

Conclusions

DP-DES are more effective in reducing very late ST and ISLL, as well as comparable to PP-DES with regard to death, TLR and MI. Further large RCTs with long-term follow-up are warranted to better define the relative merits of DP-DES.     

Use of IVUS guided coronary stenting with drug eluting stent : A systematic review and meta-analysis of randomized controlled clinical trials and high quality observational studies

Background/objectives

Long term safety of DES, particularly regarding thrombosis is of concern. The hypothesized underlying mechanisms (stent underexpansion, malapposition) could be prevented by IVUS guidance.Aim of this meta-analysis of randomized controlled clinical trials (RCT) and high quality observational cohort studies (HQ-OBS) is to quantify the potential clinical benefit of intravascular ultrasound (IVUS) guidance in drug-eluting stents (DES) implantation.

Methods

We performed an extensive literature search for full-text articles published in 2003–2013. The primary outcome was the rate of major adverse cardiac events (MACE) in RCT and HQ-OBS; secondary outcomes were death, myocardial infarction (MI), revascularization, thrombosis and post-procedural minimum lumen diameter (MLD). Fixed/random effect relative risks (RRs) or standardized mean difference (SMD) and 95% confidence interval (95% CI) were computed for the meta-analysis.

Results

Thirty-four articles were retrieved from 268 found; of these 3 were RCT and 9 were HQ-OBS; 18,707 patients were enrolled, 1037 in RCT and 17,670 in OBS. Median follow-up was 20 months. IVUS guidance was associated with a significantly lower rate of MACE (RR = 0.80, 95% CI 0.71–0.89, p < 0.001), death (RR = 0.60, 95% CI 0.48–0.74, p < 0.001), MI (RR = 0.59, 95% CI 0.44–0.80, p = 0.001) and thrombosis (RR = 0.50, 95% CI 0.32–0.80, p = 0.007) and larger MLD (SMD = 0.15, 95% CI 0.03 to 0.27, p = 0.014), but not of revascularization (RR = 0.95, 95% CI 0.82–1.09, p = 0.75).

Conclusions

In this meta-analysis, IVUS guidance in DES implantation appears to reduce MACE, mortality and MI, possibly by reducing thrombosis rather than restenosis rate. Patients at high risk for thrombosis might be identified as the best candidate for IVUS guidance.     

Drug eluting balloon versus drug eluting stent in percutaneous coronary interventions: Insights from a meta-analysis of 1462 patients

Background

Drug eluting balloons (DEB) have been developed to overcome the limitations of drug eluting stents (DES), but clinic results of various DEB studies are still not consistent. Thus, we performed a meta-analysis to compare outcomes of DEB and DES for the treatment of coronary artery disease (CAD).

Methods

Medline/Web databases were searched for studies comparing DEB and DES for obstructive CAD, reporting late lumen loss (LLL) and rates for overall mortality, myocardial infarction (MI), stent thrombosis (ST) and target lesion revascularization (TLR).

Results

8 studies (1462 patients) were included in the meta-analysis. Compared with DES, DEB treated patients showed non-significantly higher LLL (weighted mean difference [WMD] 0.32, 95% confidence interval [CI] − 0.15 to 0.78, P = 0.18) and non-significantly higher rate of binary restenosis (odds ratio [OR] 1.40 [0.68–2.48], P = 0.36). Mortality (OR 1.13[0.54–2.37], P = 0.74), MI (OR 0.95, [0.50–1.80], P = 0.87), ST (OR 1.12, [0.34–4.19], P = 0.77) and TLR rates (OR 1.19[0.60–2.38], P = 0.61) were similar between the 2 treatments. A pre-specified meta-regression analysis showed that LLL WMD and TLR OR were inversely correlated to the prevalence of diabetes (P < 0.0001) and directly correlated to reference coronary diameters (P < 0.001).

Conclusions

The present meta-analysis showed that compared to DES, DEB use resulted in similar clinical efficacy and safety. Thus DEB could be considered a reasonable alternative to DES for the treatment of CAD in selected clinical settings (Clinicaltrials.gov identifier: NCT01760200).     

A propensity score matched analysis to determine if second-generation drug-eluting stents outperform first-generation drug-eluting stents in a complex patient population

Background

Drug-eluting stents (DES) are routinely used in complex patients, but the impact of 1st- versus 2nd-generation DES on clinical outcomes has not been well described. This study aimed to assess the efficacy and safety of 2nd-generation (everolimus-eluting) DES compared to 1st-generation (sirolimus- and paclitaxel-eluting) DES in a selected, higher-risk population with complex clinical and angiographic features.

Methods

The study included 5693 consecutive patients with the presence of ≥ 1 predefined complex clinical and angiographic characteristic treated with either generation DES. Using propensity score matching, the clinical outcomes of 1076 patients treated with 2nd-generation DES were compared with the outcomes of a matched population treated with 1st-generation DES over 1-year follow-up.

Results

After matching, baseline clinical and angiographic characteristics were similar between groups. At 1-year follow-up, the rate of major adverse cardiac events was 9.4% with 2nd-generation DES and 11.3% with 1st-generation DES (p = 0.16). There were no significant differences in the rates of death (3.2 vs. 4.0%, p = 0.30), myocardial infarction (1.6 vs. 1.3%, p = 0.57), target vessel revascularization (5.9 vs. 7.3%, p = 0.17) or target lesion revascularization (4.4 vs. 5.0%, p = 0.50). Definite stent thrombosis was less frequent with 2nd-generation DES (0.1 vs. 0.8%, p = 0.011), as was definite or probable stent thrombosis (0.7 vs. 1.6%, p = 0.040).

Conclusion

In this propensity score matched patient population with complex features undergoing percutaneous coronary intervention, the use of 2nd-generation DES was associated with lower rates of stent thrombosis, and similar 1-year major adverse cardiac events compared to 1st-generation DES.     

Long-term outcome of the unrestricted use of everolimus-eluting stents compared to sirolimus-eluting stents and paclitaxel-eluting stents in diabetic patients: The Bern–Rotterdam diabetes cohort study

Background

Newer generation everolimus-eluting stents (EES) improve clinical outcome compared to early generation sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES). We investigated whether the advantage in safety and efficacy also holds among the high-risk population of diabetic patients during long-term follow-up.

Methods

Between 2002 and 2009, a total of 1963 consecutive diabetic patients treated with the unrestricted use of EES (n = 804), SES (n = 612) and PES (n = 547) were followed throughout three years for the occurrence of cardiac events at two academic institutions. The primary end point was the occurrence of definite stent thrombosis.

Results

The primary outcome occurred in 1.0% of EES, 3.7% of SES and 3.8% of PES treated patients ([EES vs. SES] adjusted HR = 0.58, 95% CI 0.39–0.88; [EES vs. PES] adjusted HR = 0.29, 95% CI 0.13–0.67). Similarly, patients treated with EES had a lower risk of target-lesion revascularization (TLR) compared to patients treated with SES and PES ([EES vs. SES], 5.6% vs. 11.5%, adjusted HR = 0.68, 95% CI: 0.55–0.83; [EES vs. PES], 5.6% vs. 11.3%, adjusted HR = 0.51, 95% CI: 0.33–0.77). There were no differences in other safety end points, such as all-cause mortality, cardiac mortality, myocardial infarction (MI) and MACE.

Conclusion

In diabetic patients, the unrestricted use of EES appears to be associated with improved outcomes, specifically a significant decrease in the need for TLR and ST compared to early generation SES and PES throughout 3-year follow-up.     

Stent thrombosis is not increased following percutaneous coronary intervention in patients with non-insulin dependent diabetes mellitus taking metformin

Objective

Recent studies have suggested that metformin may inhibit endothelialization following limus-eluting stent (LES) placement and may increase the risk of stent thrombosis. Therefore, we assessed the impact of metformin on stent thrombosis and major adverse cardiovascular events (MACE) in non-insulin-dependent diabetes mellitus (NIDDM) patients who receive drug-eluting stents (DES).

Methods

We assessed the impact of metformin and stent type on stent thrombosis, MACE, and death in NIDDM patients following DES placement. Of the 1201 patients included, 74.8% received LES, 25.2% received paclitaxel-eluting stents (PES), and 55% were taking metformin.

Results

There was no difference in stent thrombosis, regardless of stent type or metformin use. While Kaplan–Meier curves demonstrated reduced MACE (p = 0.007) and death (p = 0.006) with metformin use, multivariate analysis demonstrated that stent type and metformin use were not associated with outcome.

Conclusion

In NIDDM patients, metformin use or stent type following DES placement did not increase stent thrombosis and MACE rates.     

Two-year survival and neurological outcome of in-hospital cardiac arrest patients rescued by extracorporeal cardiopulmonary resuscitation

Background

The clinical benefit of extracorporeal cardiopulmonary resuscitation (E-CPR) has been proved in short-term follow-up studies. However, the benefit of E-CPR beyond 1 year has been not known. We investigated 2-year outcome of patients who received E-CPR or conventional CPR (C-CPR).

Methods

We analyzed a total of 406 adult in-hospital cardiac arrest victims who underwent CPR for more than 10 min from 2003 to 2009. The two-year survival and neurological outcome of E-CPR (n = 85) and C-CPR (n = 321) were compared using propensity score-matched analysis.

Results

The 2-year survival with minimal neurological impairment was 4-fold higher in the E-CPR group than the C-CPR group (23.5% versus 5.9%, hazard ratio (HR) = 0.57, 95% confidence interval (CI) = 0.43–0.75, p < 0.001) by unadjusted analysis. After propensity-score matching, it was still 4-fold higher in the E-CPR group than the C-CPR group (20.0% versus 5.0%, HR = 0.53, 95% CI = 0.36–0.80, p = 0.002). In the E-CPR group, the independent predictors associated with minimal neurological impairment were age ≤ 65 years (HR = 0.46; 95% CI = 0.26–0.81; p = 0.008), CPR duration ≤ 35 min (HR = 0.37; 95% CI = 0.18–0.76; p = 0.007), and subsequent cardiovascular intervention including coronary intervention or cardiac surgery (HR = 0.36; 95% CI = 0.18–0.68; p = 0.002).

Conclusions

The initial survival benefit of E-CPR for cardiac arrest patients persisted at 2 years.     

Optical coherence tomography analysis of strut coverage in biolimus- and sirolimus-eluting stents: 3-Month and 12-month serial follow-up

Background

No randomized studies have been conducted to investigate serial changes in optical coherence tomography (OCT) analyses following implantation of biolimus-A9-eluting stents (BES) and sirolimus-eluting stents (SES).

Methods

A total of 60 patients fulfilling the study criteria were randomly assigned into BES (n = 30) and SES (n = 30) implantation groups. Serial OCT evaluation at post-procedure, 3- and 12-month follow-up was performed in 46 patients [BES (n = 22) and SES (n = 24)]. OCT analyses were compared according to the type of stents and the follow-up time intervals. The percentage of uncovered struts was defined as the ratio of uncovered struts to total struts in all cross-sections. The primary endpoint was the percentage change (Δ) of uncovered struts in the 3- and 12-month follow-up samples.

Results

The percentage of uncovered struts at the 3-month time period was not significantly different in the BES and SES groups; the median value (interquartile range) was 14.7% (0.0–23.4) versus 8.6% (0.7–21.5) (p = 0.98), respectively. However, OCT at the 12-month follow-up showed a significantly lower percentage of uncovered struts [2.6% (0.8–5.6) versus 6.2% (1.7–14.7), (p = 0.028), respectively] without significant difference of neointimal thickness. BES showed a greater reduction of percentage Δ of uncovered struts from 3–12 months than that of SES [− 17.2 ± 14.5% versus − 7.7 ± 16.3%, respectively (p = 0.043)].

Conclusions

Both drug-eluting stents showed a high percentage of incomplete strut coverage at 3 months. However, BES showed a significantly lower percentage of uncovered struts at 12 months compared to that of SES. This was achieved by superior strut coverage from 3 to 12 months.     

Dental scaling and atrial fibrillation: A nationwide cohort study

Background

Improvement of oral hygiene through dental scaling was associated with a decreased risk of cardiovascular events. The goal of the present study was to investigate whether dental scaling can reduce the risk of atrial fibrillation (AF).

Methods

In year 2000, a total of 28,909 subjects who were age 60 or more without past history of cardiac arrhythmias were identified from the “National Health Insurance Research Database” in Taiwan. Among these subjects, those who have received dental scaling at least 1 time/year for 3 consecutive years (1998–2000) were selected to be the exposed group (n = 3391). A total of 13,564 age, sex and underlying disease-matched subjects without receiving dental scaling were identified to be the non-exposed group. The study endpoint was the occurrence of new-onset AF.

Results

During a follow-up of 4.6 ± 1.1 years, 478 participants (2.8%) developed AF. The exposed group had a lower AF occurrence rate than non-exposed group (2.2% versus 3.0%; p value = 0.017). After an adjustment with age, gender, and comorbidities in the multivariate analysis, dental scaling was associated with a reduced risk of AF (hazard ratio = 0.671, 95% CI = 0.524–0.859; p value = 0.002). Among the exposed group, the hazard ratio in developing AF was 0.340 (95% CI = 0.247–0.489; p value < 0.001) when subjects received 1 more dental scaling per year.

Conclusions

The risk of AF was lower in subjects receiving dental scaling. Improvement of oral hygiene by dental scaling may be a simple and useful way to prevent AF.     

Long-term outcomes of drug-eluting stents versus bare-metal stents in large coronary arteries

Background

Long-term (> 3 years) outcomes of drug-eluting stents (DES) versus bare-metal stents (BMS) in large coronary arteries were not conclusive. In addition, large coronary vessels were defined using a wide size range (≥ 3.0 mm) in previous studies. The aim of this study was to assess the long-term efficacy of DES versus BMS in subgroups of different vessel sizes.

Methods

A total of 1096 patients (1342 lesions) who underwent either DES or BMS implantation in large coronary vessels was followed for a mean duration of 4.5 years. Patients were divided into 4 subgroups by the reference vessel diameters (Q1: 3.0–3.25 mm, Q2: 3.26–3.50 mm, Q3: 3.51–3.75 mm, and Q4: 3.76–4.50 mm). The primary endpoint was major adverse cardiac events (MACE), defined as a composite of cardiac death, myocardial infarction, target vessel revascularization, and stent thrombosis. The propensity score-adjusted Cox regression method was applied.

Results

In the 3 subgroups with smaller vessel sizes, the adjusted risk of MACE in DES recipients was reduced by 82% in Q1 (hazard ratio [HR]: 0.18, 95% confidence interval [CI]: 0.09–0.38), 49% in Q2 (HR: 0.51, 95% CI: 0.26–0.98), and 67% in Q3 (HR: 0.33, 95% CI: 0.15–0.73). However, in the largest vessel subgroup (> 3.75 mm), all clinical outcomes were not significantly different irrespective of the stent type used.

Conclusions

The incidence of MACE in 3.0–3.75 mm vessels was significantly reduced by the use of DES than by the use of BMS during a long-term follow-up. However, DES lost its benefit in > 3.75 mm vessels.     

Comparisons of detailed arterial healing response at seven months following implantation of an everolimus- or sirolimus-eluting stent in patients with ST-segment elevation myocardial infarction

Background

The difference of arterial healing response following everolimus-eluting stent (EES) or sirolimus-eluting stent (SES) implantation in patients with ST-segment elevated myocardial infarction (STEMI) has not been compared in detail.

Methods

Thirty-five patients with STEMI were randomly implanted with an EES or SES (23 EES, 12 SES). At seven months, neointimal thickness (NIT) and strut malapposition were evaluated by optical coherence tomography (OCT) and the grade and heterogeneity of neointimal coverage (NIC) and development of intra-stent thrombi were evaluated by angioscopy.

Results

No significant differences were noted in clinical events experienced by the two groups, although one patient with an EES died following a papillary muscle rupture and one patient with a SES experienced sub-acute stent thrombosis. On OCT, although the EES implants showed a greater NIT than the SES implants (94.8 ± 88.8 μm vs 65.6 ± 63.3 μm, P < 0.0001), both the EES and SES showed an excellent suppression of neointimal proliferation in the culprit lesion of STEMI. The frequency of uncovered and malapposed struts of EES was significantly lower than that of SES (2.7% vs. 15.7%, P < 0.0001, 0.7% vs. 2.3%, P < 0.0001, respectively). The ratio of stents fully covered with neointima of EES group was significantly higher than that of SES group (P = 0.04). Angioscopic analysis also showed greater dominant NIC grade with homogenous NIC in EES than in SES (P = 0.03, P = 0.0002, respectively). The incidence of massive intra-stent thrombus of EES was lower than that of SES (P = 0.05).

Conclusion

For patients with STEMI, EES may promote better arterial healing response than SES.