Comparative effectiveness of revascularization strategies

An update on drug-eluting stents

OPINION STATEMENT

Coronary artery disease remains one of the major causes of morbidity and mortality worldwide. Percutaneous coronary intervention has been shown to be an effective treatment for angina pectoris, although it does not provide any prognostic benefit in stable patients. Drug-eluting stents (DES) have revolutionised the practice of interventional cardiology by permitting the percutaneous treatment of increasingly complex coronary artery lesions, which historically would have only been treated with surgery. There have been concerns with their long-term safety; however, the most recent large meta-analysis appears to suggest that these concerns are no longer a pertinent issue with the newest generation of stents. Consequently, DES are being used in complex patients and lesion types, and clinical data and guideline recommendations support this. New stent designs are also continually being developed, with the aim to further improve the safety profile of these devices. It must, however, be kept in mind that complacency following the impressive result from initial DES studies lead to, amongst others things, sub-optimal and careless stent deployment, and inappropriate patient selection, which may have ultimately contributed to the prior safety concerns. It is vital, therefore, that this is not repeated in light of the reassuring data, or with newer devices. Finally, as stent design improves, it is becoming increasingly difficult to identify meaningful and clinically relevant differences in stent performance without the requirement of a very large, expensive, randomised trial.

Resource use trajectories for aged medicare beneficiaries with complex coronary conditions

OBJECTIVE

To use coronary revascularization choice to illustrate the application of a method simulating a treatment's effect on subsequent resource use.

DATA SOURCES

Medicare inpatient and outpatient claims from 2002 to 2008 for patients receiving multivessel revascularization for symptomatic coronary disease in 2003-2004.

STUDY DESIGN

This retrospective cohort study of 102,877 beneficiaries assessed survival, days in institutional settings, and Medicare payments for up to 6 years following receipt of percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).

METHODS

A three-part estimator designed to provide robust estimates of a treatment's effect in the setting of mortality and censored follow-up was used. The estimator decomposes the treatment effect into effects attributable to survival differences versus treatment-related intensity of resource use.

PRINCIPAL FINDINGS

After adjustment, on average CABG recipients survived 23 days longer, spent an 11 additional days in institutional settings, and had cumulative Medicare payments that were $12,834 higher than PCI recipients. The majority of the differences in institutional days and payments were due to intensity rather than survival effects.

CONCLUSIONS

In this example, the survival benefit from CABG was modest and the resource implications were substantial, although further adjustments for treatment selection are needed.

Update on ischemic heart disease and critical care cardiology

This article summarizes the main developments reported during the year 2012 concerning ischemic heart disease, together with the most relevant innovations in the management of acute cardiac patients.

The society of thoracic surgeons national database

AIMS

The Society of Thoracic Surgeons (STS) National Database collects detailed clinical information on patients undergoing adult cardiac, paediatric and congenital cardiac, and general thoracic surgical operations. These data are used to support risk-adjusted, nationally benchmarked performance assessment and feedback; voluntary public reporting; quality improvement initiatives; guideline development; appropriateness determination; shared decision making; research using cross-sectional and longitudinal registry linkages; comparative effectiveness studies; government collaborations including postmarket surveillance; regulatory compliance and reimbursement strategies.

INTERVENTIONS

All database participants receive feedback reports which they may voluntarily share with their hospitals or payers, or publicly report. STS analyses are regularly used as the basis for local, regional and national quality improvement efforts.

POPULATION

More than 90% of adult cardiac programmes in the USA participate, as do the majority of paediatric cardiac programmes, and general thoracic participation continues to increase. Since the inception of the Database in 1989, more than 5 million patient records have been submitted.

BASELINE DATA

Each of the three subspecialty databases includes several hundred variables that characterise patient demographics, diagnosis, medical history, clinical risk factors and urgency of presentation, operative details and postoperative course including adverse outcomes.

DATA CAPTURE

Data are entered by trained data abstractors and by the care team, using detailed data specifications for each element.

DATA QUALITY

Quality and consistency checks assure accurate and complete data, missing data are rare, and audits are performed annually of selected participant sites.

ENDPOINTS

All major outcomes are reported including complications, status at discharge and mortality.

DATA ACCESS

Applications for STS Database participants to use aggregate national data for research are available at http://www.sts.org/quality-research-patient-safety/research/publications-and-research/access-data-sts-national-database.

Long-Term Mortality of 306,868 Patients with Multi-Vessel Coronary Artery Disease: CABG versus PCI

Background

Several randomized controlled trials (RCT) have reported no difference in long-term mortality between coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI). The purpose of this pooled observational analysis was to compare recent retrospective studies examining long-term survival of patients with multi-vessel coronary artery disease undergoing CABG and PCI.

Methodology

We searched Medline for observational studies comparing long-term (>1 year) survival between CABG and PCI for the treatment of multi-vessel coronary artery disease over the past 10 years.

Results

Eight studies met inclusion criteria. A total of 306,868 patients (155,502 CABG; 151,366 PCI) were identified. Follow-up ranged from 1 to 8 years. Mantel-Haenszel combined hazard ratios (HR) for mortality demonstrated a protective benefit of CABG compared with PCI (HR=0.77, 95%CI=0.75–0.79).

Conclusion

These findings suggest a long-term survival advantage for CABG compared with PCI in patients with multi-vessel coronary artery disease.

Anaortic, total-arterial, off-pump coronary artery bypass surgery: why bother?

Coronary artery bypass grafting (CABG) remains the standard of care for multi-vessel coronary disease. However, the increased rate of peri-operative stroke reported after surgery compared to percutaneous coronary intervention (PCI) remains of concern. Anaortic, total-arterial, off-pump coronary artery bypass (OPCAB) grafting is a technique that offers the main advantages of surgical revascularisation with a rate of stroke that is equivalent to that of PCI. Some recent trials comparing conventional on-pump CABG with OPCAB have questioned the efficacy of the off-pump technique - these are most often performed with manipulation of the ascending aorta. We review the potential benefits of the anaortic, total-arterial OPCAB technique to explain why it is being employed by an increasing number of surgeons.

A contemporary view of diagnostic cardiac catheterization and percutaneous coronary intervention in the United States: a report from the CathPCI Registry of the National Cardiovascular Data Registry, 2010 through June 2011

OBJECTIVES

This study sought to provide a report to the public of data from the CathPCI Registry of the National Cardiovascular Data Registry.

BACKGROUND

The CathPCI Registry collects data from approximately 85% of the cardiac catheterization laboratories in the United States.

METHODS

Data were summarized for 6 consecutive calendar quarters beginning January 1, 2010, and ending June 30, 2011. This report includes 1,110,150 patients undergoing only diagnostic cardiac catheterization and 941,248 undergoing percutaneous coronary intervention (PCI).

RESULTS

Some notable findings include, for example, that on-site cardiac surgery was not available in 83% of facilities performing fewer than 200 PCIs annually, with these facilities representing 32.6% of the facilities reporting, but performing only 12.4% of the PCIs in this data sample. Patients 65 years of age or older represented 38.7% of those undergoing PCI, with 12.3% being 80 years of age or older. Almost 80% of PCI patients were overweight (body mass index ≥25 kg/m(2)), 80% had dyslipidemia, and 27.6% were current or recent smokers. Among patients undergoing elective PCI, 52% underwent a stress study before the procedure, with stress myocardial perfusion being used most frequently. Calcium scores and coronary computed tomography angiography were used very infrequently (<3%) before diagnostic or PCI procedures. Radial artery access was used in 8.3% of diagnostic and 6.9% of PCI procedures. Primary PCI was performed with a median door-to-balloon time of 64.5 min for nontransfer patients and 121 min for transfer patients. In-hospital risk-adjusted mortality in ST-segment elevation myocardial infarction patients was 5.2% in this sample.

CONCLUSIONS

Data from the CathPCI Registry provide a contemporary view of the current practice of invasive cardiology in the United States.

Ten-year outcomes of patients randomized to surgery, angioplasty, or medical treatment for stable multivessel coronary disease: effect of age in the Medicine, Angioplasty, or Surgery Study II trial

OBJECTIVE

With progressive aging, coronary artery disease has been diagnosed at more advanced ages. Although patients aged 65 years or more have been referred to surgical or percutaneous coronary interventions, the best option for coronary artery disease treatment remains uncertain. The current study compared the 3 treatment options for coronary artery disease in patients aged 65 years or more and analyzed the impact of age in treatment options.

METHODS

Patients were separated according to age: 65 years or more (n = 200) and less than 65 years (n = 411). All patients were followed for 10 years. The rates of overall mortality, acute myocardial infarction, and new revascularizations were analyzed.

RESULTS

Of 200 patients aged 65 years or more, 68 were randomized to medical therapy, 68 were randomized to percutaneous coronary intervention, and 64 were randomized to coronary artery bypass grafting. At 10 years, overall survival was 63% (medical therapy), 69% (percutaneous coronary intervention), and 66% (coronary artery bypass grafting) (P = .93). The survival free of combined events was 43% (medical therapy), 38% (percutaneous coronary intervention ), and 66% (coronary artery bypass grafting) (P = .007). The survival free of myocardial infarction was 82% (medical therapy), 77% (percutaneous coronary intervention), and 90% (coronary artery bypass grafting) (P = .17), and survival free of new revascularizations was 59% (medical therapy), 58% (percutaneous coronary intervention ), and 91% (coronary artery bypass grafting) (P = .0003). When the 2 age groups were compared, survival free of myocardial infarction for patients treated by percutaneous coronary intervention was 77% (older patients) and 92% (younger patients) (P = .004).

CONCLUSIONS

In this analysis, treatment options for patients aged 65 years or more who have coronary artery disease yield similar overall survival. However, coronary artery bypass grafting was associated with fewer coronary events, and percutaneous coronary intervention was associated with a higher incidence of myocardial infarction.

Changes in the safety paradigm with percutaneous coronary interventions in the modern era: Lessons learned from the ASCERT registry

In the past, comparative effectiveness trials evaluating percutaneous coronary interventions (PCI), using either balloon angioplasty or bare metal stent (BMS) implantation, versus coronary artery bypass surgery (CABG) found similar survival rates at long-term follow-up with both revascularization strategies. Two major meta-analyses of these trials reported 5- and 6-year comparative effectiveness between PCI and CABG: one included only four trials that compared PCI with BMS implantation versus CABG whereas the largest one also included trials using balloon angioplasty. In these studies, the authors observed no survival differences between groups although a significant survival advantage was seen in diabetics treated with CABG and this benefit was also perceived in elderly patients. In both reports, number of involved vessels, presence of left anterior descending artery stenosis or poor left ventricular ejection fraction were no predictors of poor survival with PCI. Therefore, extent of the coronary artery disease (CAD) was not associated with poor outcome after PCI in the pre-drug eluting stent (DES) era. Recently, the ASCERT (Database Collaboration on the Comparative Effectiveness of Revascularization Strategies) registry found higher mortality rate with PCI in patients ≥ 65 years old in comparison with CABG, and advantages of surgery were seen in all subgroups including those at low risk. In this registry, PCI was accomplished by implantation of the first type of DES designs in 78% of cases. The intriguing observation of high mortality rate with PCI, including for non-diabetics and patients with two-vessel CAD, meaning a lack of clinical benefit with DES implantation, had not been seen previously. The study was not randomized, although its results are largely strengthened by its sample size. In this manuscript, the authors describe other registries and randomized trials reporting similar results supporting the findings of the aforementioned study and explore the reasons for these results, while also searching for potential solutions.

CABG in 2012: Evidence, practice and the evolution of guidelines

Abstract: In the management of coronary artery disease (CAD) it is important to ensure that all patients are receiving optimal medical therapy irrespective of whether any intervention, by stents or surgery, is planned. Furthermore it is important to establish if a proposed intervention is for symptomatic and/or prognostic reasons. The latter can only be justified if there is demonstration of a significant volume of ischaemia (>10% of myocardial mass). Taking together evidence from the most definitive randomized trial and its registry component (SYNTAX), almost 79% of patients with three vessel CAD and almost two thirds of patients with LMS disease have a survival benefit and marked reduction in the need for repeat revascularisation with CABG in comparison to stents, implying that CABG is still the treatment of choice for most of these patients. This conclusion which is apparently at odds with the results of most previous trials of stenting and surgery but entirely consistent with the findings of large propensity matched registries can be explained by the fact that SYNTAX enrolled ‘real life’ patients rather than the highly select patients usually enrolled in previous trials. SYNTAX also shows that for patients with less severe coronary artery disease there is no difference in survival between CABG and stents but a lower incidence of repeat revascularisation with CABG. At three years, SYNTAX shows no difference in stroke between CABG and stents for three-vessel disease but a higher incidence of stroke with CABG in patients with left main stem disease. In contrast the PRECOMBAT trial of stents and CABG in patients with left main stem disease showed no excess of mortality or stroke with CABG in comparison to stents in relatively low risk patients. Finally the importance of guidelines and multidisciplinary/heart teams in making recommendations for interventions is emphasised.

Alpha-crystallin: an ATP-independent complete molecular chaperone toward sorbitol dehydrogenase

alpha-Crystallin, the major component of the vertebrate lens, is known to interact with proteins undergoing denaturation and to protect them from aggregation phenomena. Bovine lens sorbitol dehydrogenase (SDH) was previously shown to be completely protected by alpha-crystallin from thermally induced aggregation and inactivation. Here we report that alpha-crystallin, in the presence of the SDH pyridine cofactor NAD(H), can exert a remarkable chaperone action by favoring the recovery of the enzyme activity from chemically denaturated SDH up to 77%. Indeed, even in the absence of the cofactor, alpha-crystallin present at a ratio with SDH of 20:1 (w:w) allows a recovery of 35% of the enzyme activity. The effect of ATP in enhancing alpha-crystallin-promoted SDH renaturation appears to be both nonspecific and to not involve hydrolysis phenomena, thus confirming that the chaperone action of alpha-crystallin is not dependent on ATP as energy donor.