Is direct coronary stenting the best strategy for long-term outcome? Results of the multicentric randomized benefit evaluation of direct coronary stenting (BET) study

Douglas Altman's 2009 Grand Lecture: Can we trust our literature?

Recent studies of the medical literature have revealed numerous and serious problems. Errors in the design, methods and interpretation of studies can frequently be identified. A huge hidden problem is publication bias, the tendency for positive articles to be published, while negative articles are either not written or submitted. This can systematically lead to an overestimation of the value of treatments, of diagnostic or prognostic studies. Even more worrisome is selective reporting: only a subset of a wide array of tested hypotheses are presented (the ones that turned out to be positive with significance testing). This is particularly true for secondary endpoints and subgroup findings, but even the primary endpoints of trials have been modified when publications are compared to protocols. The peer-review process is fallible. Even if it were strengthened, reviewers cannot examine what is not reported. Hence many problems can only be mitigated with better reporting. Numerous initiatives have proposed guidelines to promote transparent reporting, but progress is slow.

Comparing Direct Stenting With Conventional Stenting in Patients With Acute Coronary Syndromes

Our aim was to compare direct stenting (DS) with conventional stenting (CS) in patients with acute coronary syndrome (ACS). We searched PubMed, EMBASE, and ISI web of science for eligible studies. Primary end point was major adverse cardiac events (MACEs) in short term. Secondary end points were 1-year mortality and after-procedural no-reflow phenomenon. Twelve trials in 8998 patients were included. The odds ratios (ORs) were pooled using the Mantel-Haenszel fixed effect model. Short-term MACEs were significantly reduced in the DS arm in contrast to the CS (5.00% vs 8.08%, DS vs CS, respectively, OR [95% confidence interval] = 0.61 [0.46-0.80], P = .0004). One-year mortality and after-procedural no-reflow phenomenon were significantly lower in the DS group. No heterogeneity was observed through I2 test ( Phet = .81, .89, and .77 for each end point, respectively). This meta-analysis demonstrated that in selected patients with ACS, DS is not only safe and feasible but also reduces short-term and 1-year mortality as well as the occurrence of after-procedural no-reflow phenomenon.

New approach to direct stenting using a novel "all-in-one" coronary stent system via 5 French diagnostic catheters: a pilot study

OBJECTIVES

We sought to evaluate the strategy success and short term clinical outcomes of direct stenting via 5 French (F) diagnostic catheters using a novel bare metal stent with integrated delivery system (IDS) (Svelte Medical Systems, New Providence, NJ) and compare the results to a conventionally treated matched group.

METHODS

Fifteen consecutive patients with lesions deemed suitable for direct stenting using a bare metal stent were included. The primary endpoint was the strategy success defined as the ability to successfully treat a target lesion via a 5 F diagnostic catheter with a good angiographic result (TIMI III flow, residual stenosis ≤20%). Procedure and fluoroscopy times, contrast agent use, cost, and short-term clinical outcomes were compared to a matched group treated via conventional stenting.

RESULTS

The primary endpoint was reached in 14/15 patients (93%). There were no significant differences in procedural (58.6 min ± 12.7 vs. 57.4 min ± 14.2) or fluoroscopy times (10.0 min ± 4.3 vs.10.1 min ± 3.9) or contrast agent use (193.7 ml ± 54.8 vs. 181.4 ml ± 35.6). However, there were significant reductions in materials used in the study group compared to the control group equating to cost savings of almost US $600 per case (US $212.44 ± 258.09 vs. US $804.69 ± 468.11; P = 0.001).

CONCLUSIONS

Direct stenting using a novel bare metal stent with an IDS via 5 F diagnostic catheters is a viable alternative to conventional stenting in selected patients and is associated with significant cost savings.

Treating and preventing no reflow in the cardiac catheterization laboratory

The no reflow phenomenon can happen during elective or primary percutaneous coronary intervention. This phenomenon is thought to be a complex process involving multiple factors that eventually lead to microvascular obstruction and endothelial disruption. Key pathogenic components include distal atherothrombotic embolization, ischemic injury, reperfusion injury, and susceptibility of coronary microcirculation to injury. Thus, pharmacologic and mechanical strategies to prevent and treat no reflow target these mechanisms. Specifically, pharmacologic therapy consisting of vasodilators and antiplatelet agents have shown benefit in the treatment of no-reflow and mechanical therapies such as distal protection and aspiration thrombectomy have also shown benefit.

The independent value of a direct stenting strategy on early and late clinical outcomes in patients undergoing elective percutaneous coronary intervention

OBJECTIVES

This study aimed to compare percutaneous coronary intervention (PCI) with direct stenting (DS) to balloon predilatation (PD) for patients undergoing elective PCI to determine whether there is an independent value for DS with regard to clinical outcomes.

BACKGROUND

The safety of PCI with DS has been established, but the independent advantages of this technique are not entirely clear.

METHODS

Patients undergoing elective PCI from January 2000 to December 2010 were included. The postprocedural and late clinical outcomes of 444 patients who underwent PCI with DS were compared with a propensity-matched population of 444 subjects treated with PD.

RESULTS

The two groups were well matched to 27 baseline clinical, procedural, and angiographic characteristics, thus allowing for a more accurate evaluation of the independent value of the stenting technique. Intravascular ultrasound was used in more than 60% of interventions in both groups. PCI performed with PD were longer (DS 45 ± 19.28 vs. PD 56 ± 23.72 minutes, P = 0.001), used more contrast (DS 154 ± 65.88 vs. PD 186 ± 92.84 cc, P = 0.001), and more frequently used balloon postdilation (DS 0% vs. PD 27.3%, P = 0.001). The incidence of periprocedural myocardial infarction (PPMI) was similar between DS- and PD patients (5.3% vs. 5.4%, P = 0.91). Likewise, the 1-year rates of major adverse cardiac events (8.4% vs. 6.3%, P = 0.25), target lesion revascularization (3.9% vs. 2.5%, P = 0.24), and definite stent thrombosis (0.2% vs. 0.9%, P = 0.37) were similar among DS and PD patients, respectively.

CONCLUSION

During elective PCI, DS decreases overall procedure time and resource utilization, but fails to reveal an independent clinical advantage as there is no demonstrable benefit in regard to the incidence of PPMI, restenosis, or overall clinical outcomes up to 1-year of follow-up.

Direct stenting versus predilatation and stenting technique when using paclitaxel-eluting stents

Direct stenting without predilatation is a well-defined, feasible method with bare metal stents. Direct stenting has also been shown to be safe and feasible with drug-eluting stents, however, there is much less evidence with this type of device when compared with bare metal stents. Three hundred and sixty-four coronary lesions in 257 consecutive patients (mean age, 57.4 +/- 9.8 years; 63 women) who had undergone elective stenting either with or without predilatation via a paclitaxel-eluting stent between March 2003 and March 2006 were retrospectively analyzed. Quantitative coronary angiography analysis was compared between the two groups of procedures; stenting with predilatation and direct stenting. All procedures were uneventful. No deaths occurred during the follow-up period. Direct stenting when compared with the predilatation technique, significantly decreased both procedure time (32.1 +/- 17.9 minute versus 41.2 +/- 18.6 minute, P < 0.0001) and fluoroscopy time (10.6 +/- 7.8 minute versus 15.5 +/- 7.6 minute, P < 0.0001). There was no difference in quantitative analysis parameters of coronary angiography during follow-up or the rates of stent thrombosis and restenosis. Direct stenting seems to be as feasible and safe as conventional predilatation and stenting in selected cases. Direct stenting seems to decrease procedural time and radiation exposure without any negative effect on quantitative analysis parameters of coronary angiography with approximately a one-year follow-up period.

Comparison of outcomes of direct stenting versus stenting after balloon predilation in patients with acute myocardial infarction (DIRAMI)

Due to recent advances in stent design, stenting without balloon predilation (direct stenting) has become more extensively used in patients with acute myocardial infarction (AMI). We performed a randomized study with broad inclusion criteria and early randomization after presentation to compare direct stenting with stenting after balloon predilation in patients with AMI. A total of 248 patients was randomized. After exclusion of patients not suitable for stenting, the final study group comprised 217 patients. Direct stenting strategy was feasible in 88% of patients with no meaningful complications. Final Thrombolysis In Myocardial Infarction grade 3 flow (96% vs 94%), final Thrombolysis In Myocardial Infarction myocardial perfusion grade 2 or 3 (68% vs 61%), and average ST-segment resolution after the procedure (49% vs 51%) were similar in the direct stenting and predilation groups, respectively (p = NS). Rate of in-stent restenosis was higher in the direct stenting group (30% vs 16%, p = 0.024), which was due to a worse angiographic result after the procedure. At 5 years, a composite of cardiac death, reinfarction, and target lesion revascularization had occurred in 39% in the direct stenting group and 34% in the predilated group (p = 0.40). In conclusion, although at 5 years clinical outcome did not differ significantly between groups, direct stenting was associated with a higher incidence of in-stent restenosis at 1 year. Direct stenting did not improve epicardial and myocardial reperfusion indexes. Direct stenting strategy should not be recommended in all patients with AMI as an alternative strategy to stenting after predilation.

The SIRIUS-DIRECT trial: A multi-center study of direct stenting using the sirolimus-eluting stent in patients with de novo native coronary artery lesions

OBJECTIVE

To assess the safety and efficacy of direct stenting using the sirolimus-eluting BX Velocitytrade mark stent in patients with coronary lesions.

BACKGROUND

Although direct coronary stenting has become a widespread practice, there have been no systematic assessments of direct stenting with drug-eluting stents.

METHODS

Total of 225 patients with identical inclusion and exclusion criteria as the original SIRIUS trial were enrolled in this prospective single-arm study. They were compared in a no-inferiority design with 412 similar patients from the SIRIUS trial who had sirolimus-eluting stents deployed after predilatation and were preassigned to angiographic follow-up evaluation.

RESULTS

Direct stenting was successful in 85.8% of the patients. Compared with the predilatation group, direct stenting was associated with shorter median procedure duration (33 min vs. 45 min, P < 0.001). Angiographic follow-up at 8 months revealed similar late loss (in-stent-0.19 +/- 0.47 mm vs. 0.17 +/- 0.44 mm, and in-lesion-0.23 +/- 0.41 mm vs. 0.24 +/- 0.47 mm) and similar frequency of binary restenosis (in-stent-4.6% vs. 3.2% and in-lesion-6.1% vs. 8.9%) between the two treatment strategies. However, stent-edge restenosis was lower with direct stenting than in the predilatation control group (2.1% vs. 6.9%, P = 0.02). At 12-months, there were no significant differences in target lesion revascularization (3.7% vs. 5.1%, P = ns) or composite major adverse cardiac events (7.0% vs. 8.3%, P = ns).

CONCLUSIONS

In patients similar to those treated in the SIRIUS trial, direct stenting using sirolimus-eluting stents achieves excellent short- and long-term clinical and angiographic results with shorter procedure time and less frequent stent edge restenosis compared with predilation stent implantation techniques.

Subgroup analyses in therapeutic cardiovascular clinical trials: are most of them misleading?

BACKGROUND

Treatment decisions in clinical cardiology are directed by results from randomized clinical trials (RCTs). We studied the appropriateness of the use and interpretation of subgroup analysis in current therapeutic cardiovascular RCTs.

METHODS

We reviewed main reports of phase 3 cardiovascular RCTs with at least 100 patients, published in 2002 and 2004, and from major journals (Circulation, J Am Coll Cardiol, Am Heart J, Am J Cardiol, N Engl J Med, Lancet, JAMA, BMJ, Ann Intern Med). Information on subgroups included prespecification, number, interaction test use, significant subgroups found, and emphasis on findings. We examined appropriateness of reporting and differences according to sample size, overall trial result, and CONSORT adoption.

RESULTS

We selected 63 RCTs, with a median of 496 (range 100-15,245) patients. Thirty-nine RCTs were reported with subgroup analyses and 26 with > 5 subgroups. No trial was specifically powered to detect subgroup effects, and only 14 RCTs were reported with fully prespecified subgroups. Only 11 RCTs were reported with interaction tests. Furthermore, 21 RCTs were reported with claims of significant subgroups and 15 with equal or more emphasis to subgroups than to the overall results. Subgroup analyses in large RCTs (> 500 patients) were reported more often than in small ones (24/30 vs 15/33, P = .005). No differences were found according to overall result (positive/negative) or CONSORT adoption.

CONCLUSIONS

Subgroup analyses in recent cardiovascular RCTs were reported with several shortcomings, including a lack of prespecification and testing of a large number of subgroups without the use of the statistically appropriate test for interaction. Reporting of subgroup analysis needs to be substantially improved because emphasis on these secondary results may mislead treatment decisions.

Improving Design and Analysis of Research: Lessons from Clinical Research

There is a clear need to optimise the use of animals in research and to ensure that the studies that are done make a worthwhile contribution to scientific knowledge. Research that has an inappropriate study design, or is improperly analysed or interpreted, may mislead and is not defensible. Published reviews of the quality of design and analysis in clinical studies are used to see what lessons can be drawn in respect of animal research. The need for clear and full reporting of research is discussed.

Randomized comparison of direct stenting with predilatation followed by stenting on vessel trauma and restenosis

BACKGROUND

Direct stenting may reduce trauma to the vessel wall, thereby having a positive impact on acute and long-term results. This study evaluated acute vessel trauma and acute and follow-up angiographic and intravascular ultrasound (IVUS) results after direct stenting in comparison to conventional stenting.

METHODS

Two hundred forty-nine patients were randomly assigned to direct stenting (n = 124) or stenting after predilatation (n = 125) and were followed up by angiography at 6 +/- 2 months. Intracoronary serum endothelin (ET-1) levels were determined distal to the lesion before and after coronary intervention to define vessel trauma, and IVUS was performed before and after intervention and at follow-up to determine induced changes in vessel morphology and intimal hyperplasia in a subgroup of 40 patients.

RESULTS

Feasibility of direct stenting was 91%, with 9% requiring crossover to predilatation. There were no differences between the 2 groups in immediate clinical, angiographic, and intravascular ultrasound results. Intracoronary ET-1 levels increased significantly after intervention, without differences between the 2 groups (increase in ET-1 level, 0.79 +/- 1.06 vs 0.96 +/- 1.22 fmol/L, P =.206). At 6-month follow-up, angiographic late loss (0.76 +/- 0.86 vs 0.69 +/- 1.09 mm, P =.788) and restenosis rate (21% vs 20%, P = 1.000) were similar for direct stenting versus conventional stenting, respectively. IVUS demonstrated comparable intimal hyperplasia areas for direct versus conventional stenting (2.0 +/- 1.5 mm(2) vs 2.2 +/- 1.6 mm(2), respectively, P =.243).

CONCLUSIONS

Direct stenting is highly feasible and results in similar vessel trauma and change in vessel morphology and acute lumen dimensions compared with stenting after predilatation. Similar acute angiographic and IVUS results persist at 6-month follow-up.