Are Drug-Eluting Stents the Preferred Treatment for Multivessel Coronary Artery Disease?

Treatment variation in stent choice in patients with stable or unstable coronary artery disease

AIM

Variations in treatment are the result of differences in demographic and clinical factors (e.g. anatomy), but physician and hospital factors may also contribute to treatment variation. The choice of treatment is considered important since it could lead to differences in long-term outcomes. This study explores the associations with stent choice: i.e. drug-eluting stent (DES) versus bare-metal stents (BMS) for Dutch patients diagnosed with stable or unstable coronary artery disease (CAD).

METHODS & RESULTS

Associations with treatment decisions were based on a prospective cohort of 692 patients with stable or unstable CAD. Of those patients, 442 patients were treated with BMS or DES. Multiple logistic regression analyses were performed to identify variables associated with stent choice. Bivariate analyses showed that NYHA class, number of diseased vessels, previous percutaneous coronary intervention, smoking, diabetes, and the treating hospital were associated with stent type. After correcting for other associations the treating hospital remained significantly associated with stent type in the stable CAD population.

CONCLUSIONS

This study showed that several factors were associated with stent choice. While patients generally appear to receive the most optimal stent given their clinical characteristics, stent choice seems partially determined by the treating hospital, which may lead to differences in long-term outcomes.

Long-term Outcomes of Drug-eluting Stents in Symptomatic Intracranial Stenosis

Purpose

The use of drug-eluting stent (DES) to treat intracranial stenosis has shown short-term success. However, there are no reports regarding the long-term results of DES. We present the long-term clinical outcome after DES stenting for symptomatic severe intracranial stenosis.

Materials and Methods

Our study included a consecutive series of 11 patients who underwent intracranial stenting using DES between March and July, 2006, during the time when bare metal stents were not available at our medical institution. The mean patient age was 59 years. Lesion location was the middle cerebral artery in five patients, the intradural vertebral artery in three, the basilar artery in one, the vertebrobasilar junction in one, and the cavernous internal cerebral artery in one patient. We evaluated the technical success, defined as reduction of residual stenosis ≤30% in the target lesion) as well as the clinical and imaging outcomes as long as 75 months following the procedure. In addition to a cerebral angiogram (n = 2), follow-up study was obtained by CT angiography (n = 6) or intracranial Doppler imaging (n = 2) during a mean time of 55 months after the procedure (range, 24 to 73 months). Three patients refused imaging follow-up and accepted only clinical follow-up. The mean clinical follow-up period was 67 months (range, 47-75 months).

Results

Stenting in all patients was technically successful and without periprocedural complications. There was thrombus formation during the procedure in one patient who experienced no further complications. There were no new neurological events during the mean follow-up period of 5.6 years. No patients were found to have restenosis ≥50% at during the mean follow-up period of 55 months. One patient died of a sudden heart attack 59 months following the procedure which was regarded as unrelated to the cerebral lesion.

Conclusion

Our study demonstrates that DES shows long-term stability and safety, and results in good clinical outcomes with a low rate of restenosis.

Prognosis of percutaneous coronary intervention and coronary artery bypass grafts for ostial right coronary lesions in propensity-matched individuals

OBJECTIVE

Our aim was to evaluate the relative safety and efficacy of percutaneous coronary intervention (PCI) with drug-eluting stents (DES) versus coronary artery bypass grafts (CABG) for the treatment of ostial right coronary stenosis (ORCS) lesions.

METHODS

Three hundred fifty-nine cases of ORCS lesion were treated via CABG (n = 232) or PCI (n = 127) procedures. Propensity scores for undergoing the CABG procedure were estimated and used to match 105 pairs of patients between the two groups. Kaplan-Meier major adverse cardiac and cerebrovascular events (MACCE)-free curves were constructed to compare long-term MACCE-free survival between the two groups.

RESULTS

For the 105 propensity-matched pairs, patients were more likely to undergo repeat revascularization with CABG in the PCI group than in the CABG group during the first 30 days (4 cases vs. 0 case, P= 0.043, χ(2) = 4.08) and the 1-year follow-up (5 cases vs. 0 case, P= 0.02, χ(2) = 5.17). With a mean follow-up of 12.04 ± 6.47 months and a total of 210.67 patient-years, the freedom from MACCE in the CABG group was significantly higher than that in the PCI group (Log rank test, χ(2) = 4.48, P= 0.03). There were no significant differences in the rates of death, myocardial infarction, nonfatal stroke, death/myocardium infarction/stroke, or repeated PCI between the two groups during the first 30 days and during the 1-year follow-up period.

CONCLUSION

For OCRS lesions, CABG provided greater protection than PCI procedure in terms of freedom from MACCE, mainly due to the reduced number of repeated revascularization procedures. CABG should be considered as first-choice revascularization strategy for ORCS lesions.

Intracranial atherosclerotic disease; current options for surgical or medical treatment

Recently, intracranial atherosclerosis has become a major cause of ischemic stroke, appearing more frequently in Koreans than Caucasians. Symptomatic or asymptomatic intracranial atherosclerosis is a disease that could recur readily even during the treatment with anti-platelet agents. When the symptoms develop, ischemic stroke can not be recovered readily. Therefore, aggressive treatments such as endovascular therapy and bypass surgery are required in addition to medical treatment for the intracranial artery stenosis. Recent intracranial stenting and drug eluting stenting have shown as very advanced effective therapeutic modalities. Nevertheless, until now, a randomized controlled study has not been conducted. Regarding bypass surgery, since the failed EC-IC bypass surgery study performed 20 years ago, extensive studies on its efficacy has not been conducted yet, and thus it has to be performed strictly only in hemodynamically compromised patients. Unless breakthrough drugs that suppress the progression of intracranial atherosclerosis and the formation of thrombi, and facilitate the regression of the arterial stenosis, the treatment concept of the recovery of the blood flow of stenotic arterial territory by mechanical recanalization or bypass surgery would be remained for the prevention as well as treatment of ischemic stroke caused by intracranial atherosclerosis.

[Stenting or coronary artery bypass surgery for triple vessel disease?]

This review was undertaken to objectively analyse the cumulated medical literature on techniques of myocardial revascularization (angioplasty, bare metal stenting, drug eluting stenting, coronary artery surgery) in multivessel coronary artery disease. Randomized trials, meta analyses and registries comparing these treatment modalities show a short and long term advantage of surgery over percutaneous techniques for angina recurrence and need for repeat revascularization, although mortality and myocardial infarction rate do not seem statistically different. Diabetes mellitus, chronic renal failure and female gender represent high risk subgroups. Data on drug eluting stents are to date limited to the short term; however, it does not seem that drug eluting stents have resolved the need for repeat revascularization. Stenting addresses focal lesion whereas future revascularization occurs on other coronary sites by progression of coronary disease. Cardiologists should objectively inform the consenting coronary multivessel disease patient on the risk of repeat revascularization inherent to percutaneous techniques and on the weight of actual data favouring surgery in multivessel disease.

X-ray micro-tomography of a coronary stent deployed in a model artery

Coronary stents are small scaffolds routinely implanted during angioplasty procedures to re-open coronary arteries which have become narrowed by an atherosclerotic plaque. Despite the advent of drug-eluting stents to reduce restenosis (re-narrowing) after the procedure, complications still arise and mechanical factors may be partly the cause. Stents are being used in increasingly complex cases, so new forms of pre-clinical testing may be helpful in evaluating stent designs and deployment techniques. With this in mind, an in vitro experiment was conducted to evaluate the use of X-ray micro-tomography to image stents at various stages of deployment. A stent was deployed in an artificial artery while using a synchrotron X-ray source to obtain the tomography scans. A volume element (voxel) size of 5.3 microm was achieved, with a vertical field of view of 4.5mm. The imaging of the stent and artificial artery materials was better than expected, despite some attenuation artifacts and the high monochromatic beam energy used (25 keV). Experimental problems are discussed, together with recommendations for improving the technique. It is intended that this technique will be of interest to engineers and clinicians as a pre-clinical test.

Coronary artery bypass is superior to drug-eluting stents in multivessel coronary artery disease

Percutaneous intervention for the treatment of multivessel coronary artery disease continues to displace coronary artery bypass graft surgery. But controlled trials of percutaneous intervention versus coronary bypass, in meta-analysis, have shown a significant survival advantage for coronary bypass. Studies of bare metal stents have not presented any data to prompt reversal of this conclusion for all but the small portion of patients most suited for stenting. Drug-eluting stents have no survival advantage compared with bare metal stents. Data from real-world registries have shown that the current therapy of multivessel disease patients has resulted in a relative excess mortality of as much as 46% in patients with initial stenting compared with patients with initial coronary bypass. Ethical considerations demand that patients with multivessel disease be informed of the documented mortality benefit of coronary bypass graft surgery.

Myocardial revascularization: surgery or stenting?

There is current debate regarding the relative merits and roles of surgical revascularization and percutaneous revascularization for patients with obstructive coronary artery disease. This article reviews the current literature relating to this subject.

Gene therapy progress and prospects: therapeutic angiogenesis for ischemic cardiovascular disease

During the past decade, both in vitro and in vivo studies have provided new insights into the cellular and molecular mechanisms that govern angiogenesis and arteriogenesis. However, therapeutic angiogenesis clinical trials using recombinant protein or gene therapy formulations of single angiogenic growth factors have yielded at best only modest success to date. Among the second generation of angiogenic agents are therapeutic transgenes that enhance expression of two or more proangiogenic cytokines. These include synthetic constructs that mimic that activity of endogenous transcriptional regulators and other upstream, regulatory factors that have the potential to induce formation of morphologically and physiologically functional vessels. These agents are now beginning to be evaluated in clinical trials for patients with advanced ischemic cardiac and peripheral vascular disease.

Coronary Artery Bypass Surgery Versus Percutaneous Coronary Intervention with Drug-Eluting Stent Implantation in Patients with Multivessel Coronary Disease

BACKGROUND

Drug-eluting stents (DES) constitute a major breakthrough in restenosis prevention after percutaneous coronary intervention (PCI). This study compared the clinical outcomes of PCI using DES versus coronary artery bypass graft (CABG) in patients with multivessel coronary artery disease (MVD) in real-world.

METHODS

From January 2003 to December 2004, 466 consecutive patients with MVD underwent revascularization, 235 by PCI with DES and 231 by CABG. The study end-point was the incidence of major adverse cardiovascular events (MACEs) at the first 30 days after procedure and during follow-up.

RESULTS

Most preoperative characteristics were similar in the two groups, but left main disease (24.7% vs 2.6%, P<0.001) and three-vessel disease (65% vs 54%, P = 0.02) were more prevalent in CABG group. The number of coronary lesions was also greater in CABG group (3.7 +/- 1.1 vs 3.3 +/- 1.1, P<0.001). Despite higher early morbidity (3.9% vs 0.8%, P = 0.03) associated with CABG, there were no significant differences in composite MACEs at the first 30 days between the two groups. During follow-up (mean 25+/-8 months), the incidence of death, myocardial infarction, or cerebrovascular event was similar in both groups (PCI 6.3% vs CABG 5.6%, P = 0.84). However, bypass surgery still afforded a lower need for repeat revascularization (2.8% vs 10.4%, p = 0.001). Consequently, overall MACE rate (14.5% vs 7.9%, P = 0.03) remained higher after PCI.

CONCLUSION

PCI with DES is a safe and feasible alternative to CABG for selected patients with MVD. The reintervention gap was further narrowed in the era of DES. Aside from restenosis, progression of disease needs to receive substantial emphasis.

Comparison of drug-eluting versus bare metal stents on later frequency of acute myocardial infarction and death

In clinical trials of highly selected patients, drug-eluting stents (DESs) decreased restenosis but not the rate of acute myocardial infarction (AMI) or death. Whether DES use has an affect on the rate of AMI or death in unselected patients is uncertain. Bare metal stents (BMSs) were placed in 1,164 consecutive patients in the year before the introduction of DESs. DESs were subsequently placed in 1,285 consecutive comparable patients at Wake Forest Baptist Medical Center. Early and late clinical outcomes were compared. Propensity score analysis was used to adjust outcomes for baseline differences. Patient and procedural characteristics of the 2 groups were similar, with an overall incidence of 72% for acute coronary syndromes (p = NS). At 9 months, target vessel revascularization (2.8% vs 8.6%, p <0.001), AMI (3.7% vs 4.7%, p = 0.257), and death (4.9% vs 7.1%, p = 0.030) were lower in the DES group than in the BMS group. Propensity score-adjusted Cox proportional hazard ratios for DES versus BMS at 9 months were 0.71 (95% confidence interval 0.42 to 1.19) for AMI, 0.56 (95% confidence interval 0.36 to 0.87) for death, and 0.60 (95% confidence interval 0.42 to 0.86) for the combined end point of AMI or death. In conclusion, in this single-center observational study, use of DESs in consecutive unselected patients, most of whom would not have been eligible for inclusion in the randomized trials of DES versus BMS, was associated with lower AMI and death rates than in a comparable group of patients treated with BMSs in mid-term (9-month) follow-up.

Early and intermediate-term outcomes with drug-eluting stents in high-risk patients with symptomatic intracranial stenosis

OBJECTIVE

To report the 1-month and intermediate-term results of treatment of symptomatic intracranial stenosis using drug-eluting stents.

BACKGROUND

Patients with intracranial stenosis who are at high risk because of either high-grade stenosis or medication failure may have an annual risk of recurrent ischemic events in excess of 40%. Drug-eluting stents may reduce the rate of ischemic events in patients with a low restenosis rate.

METHODS

We determined rates of technical success (defined as reduction of target lesion to stenosis <30%) and 1-month major stroke or death in patients with symptomatic intracranial stenosis (> or =70% and/or medication failure). Patients' clinical and follow-up information during a mean period of 14.3 +/- 7 months were obtained. Kaplan-Meier analysis was performed to determine the rate of major stroke-free survival during 12 months.

RESULTS

There were 18 patients (mean age, 58 +/- 16 yr; 12 were men) treated with either a sirolimus-eluting stent (n = 14) or a paclitaxel-eluting stent (n = 4) for stenosis located in the: intracranial internal carotid artery (n = 6), proximal middle cerebral artery (n = 4), intracranial vertebral artery (n = 4), vertebrobasilar junction (n = 2), or basilar artery (n = 2). There was one major stroke and no death observed in the 1-month follow-up. At the 6-month follow-up examination, no major stroke or death was observed. Major stroke-free survival was 86% (+/-standard error of 9%) at 12 months after the procedure. One symptomatic angiographic restenosis was observed during the follow-up period.

CONCLUSION

A low rate of major stroke or death was observed after treatment of symptomatic intracranial stenosis using drug-eluting stents in high-risk patients.

Optimization of Device Programming for Cardiac Resynchronization Therapy

Cardiac resynchronization therapy may lead to remarkable improvement in clinical status in selected patients with heart failure. However, approximately 20-30% of patients may not respond to this treatment. One of the reasons for this may be suboptimal programming of the device, which has particular considerations as compared to standard pacemakers. Hemodynamic response to pacing may be affected by timing of the atrioventricular (AV) interval, affecting synchronicity of atrial and ventricular contraction. In addition current biventricular devices have separate right and left ventricular channels that allow programming of an interventricular (VV) interval with right or left ventricular preexcitation. This article focuses on the parameters that may be optimized for biventricular pacing, and reviews the different techniques currently available for this application, with special emphasis paid to echocardiography.