Game Changers in 2012: EuroPCR Features Studies Likely to Change Practice
Paris—Each year at EuroPCR, there is an emphasis on studies that may change clinical practice. This year, in collaboration with the ACC, three trials were selected based on great science, the attention to clinical need, the potential to change practice, and the likelihood to optimize patient care. David R. Holmes, Jr., MD, immediate past-president of the ACC, co-chaired the session and met with the press to discuss the papers.
The ACCF and the Society of Thoracic Surgeons developed a partnership called the ACCF and STS Database Collaboration on the Comparative Effectiveness of Revascularization Strategies (ASCERT). The goal was to compare the outcomes of PCI (using the ACC`s CathPCI Registry®) and CABG (using the STS database), with follow-up data from claims records of the Centers for Medicare and Medicaid Services.
The analysis of health outcomes for about 190,000 US patients between 2004 and 2008 indicated that CABG surgery is associated with better long-term survival rate than PCI. Specifically, among Medicare patients 65 years of age or older with ischemic heart disease that required revascularization on a nonemergency basis, there was no significant difference in 1-year adjusted mortality between CABG and PCI patients, but 4-year mortality was significantly lower with CABG than PCI (16.4% vs. 20.8%; risk ratio = 0.79).
The results were similar in all subgroups and survival was better following CABG, even among patients whose propensity scores were most consistent with selection for PCI.
This may be a game changer for several reasons:
- One of the best practices to arise from ASCERT is embracing this concept of the heart team approach.
- The analysis shows how observational studies can provide real-world outcomes with greater generalizability than randomized trials.
- Linking robust clinical databases with administrative databases capitalizes on the advantages of both, allowing for very large studies with power to examine subgroups.
- The major problem with observational studies is treatment selection bias, which limits use for medical decision making. For comparative effectiveness to reach its potential, randomized trials and observational studies will both play critical roles.
Dr. Holmes emphasized the role of patient-centered care, meaning "consultation and discussion with both interventional cardiology, as well as cardiovascular surgery, in conjunction with the patient and family, so that an optimal strategy can be recommended for a specific patient in the specific clinical circumstances."
2-Year PARTNER Results
Dr. Holmes also highlighted the "transformational" technology of TAVR, which is now generally accepted as the new standard for patients with symptomatic aortic stenosis who are not candidates for open surgery. While Europe has had access to TAVR for several years and compiled large registry datasets, US regulatory approval required a randomized clinical trial. PARTNER is the single randomized clinical trial in the field used for FDA approval and continues to be a rich source of data on the risk/benefit ratio of TAVR.
In high-risk operable patients (PARTNER A), mortality at 1 year was not statistically different between TAVR and surgery (SAVR) but there were differences in complication patterns; stroke, for one, increased in frequency in TAVR patients.
In inoperable patients (PARTNER B), there was significantly improved survival with TAVR compared with routine medical therapy, but also an increase in stroke and vascular access complications.
Two-year outcome data are now available:
- PARTNER A: All-cause mortality was similar between TAVR and SAVR (p = 0.692), as was improvement in valve area. While TAVR was associated with increased stroke at 30 days (4.6% vs. 2.4%), at 2 years the incidence of total stroke was not significantly different for the two approaches (p = 0.517), with no late (post-30 days) stroke in the TAVR group.
- PARTNER B: Outcomes remain significantly better with TAVR compared with standard therapy in the operable group. Cardiac death was 31.0% and 62.4% respectively (p < 0.001), and all-cause mortality was 43.3% and 68.0%. The rate of stroke remained higher with TAVR (13.8% vs. 5.5%; p = 0.01), but TAVR patients had significantly fewer rehospitalizations and better functional class.
Myocardial recovery after primary PCI is often suboptimal despite restoration of TIMI 3 flow. This may be due to thrombus embolization, impaired microvascular perfusion, or increased infarct size. Two strategies have been proposed to reduce embolization after primary PCI: bolus intracoronary (IC) abciximab and manual thrombus aspiration. However, prior studies have led to conflicting results; perhaps due to enrollment of a high proportion of small infarcts (e.g., non-anterior and/or with TIMI 3 flow).
The INFUSE AMI study evaluated the benefits and safety of IC abciximab and aspiration thrombectomy during primary PCI in patients with large anterior MI treated with bivalirudin. Investigators randomized 454 patients to one of four arms: 1) aspiration with export aspiration catheter followed by an IC abciximab bolus; 2) IC abciximab bolus without aspiration thrombectomy; 3) aspiration without IC abciximab; or 4) neither IC abciximab or aspiration.
In these patients presenting early in the course of an evolving anterior STEMI, bolus IC abciximab delivered to the lesion site via the ClearWay Rx Infusion Catheter resulted in a significant but modest reduction in infarct size at 30 days (primary endpoint). This reduction however, did not affect 30-day safety or clinical efficacy. Manual aspiration with the 6F Export Catheter did not reduce infarct size.
An important implication of this study, said Dr. Holmes, is that bolus IC abciximab using an aspiration catheter reduces infarct size but does not impact outcomes. The utility of combined aspiration plus local delivery of IC abciximab deserves further study. The final word on aspiration in STEMI awaits the results of the ongoing randomized TOTAL (N = 4,000) and TASTE (N = 5,000) trials.
Keywords: Odds Ratio, Myocardial Ischemia, Stroke, Follow-Up Studies, Propensity Score, Referral and Consultation, Centers for Medicare and Medicaid Services, U.S., Immunoglobulin Fab Fragments, Hirudins, Patient-Centered Care, Incidence, Registries, Thrombectomy, Selection Bias, Thrombosis, Survival Rate
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