Platelet Activity Measured by VerifyNow® Aspirin Sensitivity Test Identifies Coronary Artery Bypass Surgery Patients at Increased Risk for Postoperative Bleeding and Transfusion.

BACKGROUND: Identifying predictors of bleeding in patients before coronary artery bypass grafting surgery is important, given the complications of bleeding and finite supply of blood. Patient response to aspirin is heterogeneous and can be evaluated using point-of-care platelet function tests. We postulated that patients who hyper-respond to aspirin given preoperatively, as identified by VerifyNow® Aspirin assay (Accumetrics, Inc., San Diego, CA, USA), are at increased risk of bleeding and transfusion. METHODS: This prospective pilot study examined response to aspirin in patients undergoing coronary artery bypass grafting surgery (n = 61) from 2009 to 2013. Patients with aspirin reaction unit (ARU) values in the lower 50th percentile as identified by VerifyNow® assays were defined as aspirin hyper-responders. The proportion of patients transfused and the median adjusted indexed drop in haemoglobin were compared between aspirin hyper-responders and non-hyper-responders. Logistic regression was performed to determine factors associated with increased risk of transfusion. RESULTS: Seventy per cent (70%) of aspirin hyper-responders were transfused perioperatively compared with 39% of patients who did not hyper-respond, (OR 3.694, 95% CI 1.275-10.706, p = 0.014). VerifyNow® Aspirin hyper-responders had a greater median adjusted indexed drop in haemoglobin compared to non-hyper-responders (34.1 g/L versus 26.6 g/L respectively, p = 0.032). Multivariate analysis also showed VerifyNow® Aspirin hyper-response to be an independent predictor of transfusion (p = 0.016). Other variables such as age, gender, body mass index, renal insufficiency, and cross clamp and bypass times were not predictors of postoperative bleeding in this pilot cohort. CONCLUSIONS: VerifyNow® Aspirin is able to preoperatively identify aspirin hyper-responders at an increased risk of bleeding and subsequent transfusion in the context of coronary artery bypass graft surgery.

Late clinical outcomes of unselected patients with diabetic mellitus and multi-vessel coronary artery disease.

BACKGROUND: The Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multi-Vessel Disease (FREEDOM) clinical trial randomized only a proportion of screened patients with diabetes mellitus (DM) and multi-vessel disease (MVD). METHODS AND RESULTS: We determined late rates of death, non-fatal myocardial infarction (MI) and stroke in all 430 patients with DM who had MVD identified on angiographic screening for the FREEDOM Trial, which recruited from June 2006 -March 2010 at Liverpool Hospital, Sydney, Australia. Mortality at 6 years [median] was 23% among 192 FREEDOM-eligible patients and 26% among 238 FREEDOM-ineligible patients, of whom 139 [58%] had prior. CABG (mortality 31%). Overall, 196 (45%) had percutaneous coronary intervention (PCI), 127 (30%) underwent coronary artery bypass grafting (CABG) (who were 4 years younger; p = 0.003), and 107 (25%) had neither procedure of whom 80 were considered unsuitable for revascularization. Mortality was 26% post-PCI 16%, post-CABG and 33% among those who did not undergo revascularization (p = 0.01). On multivariable analyses, factors associated with late mortality were older age, hypertension and not undergoing CABG (all p < 0.05). Factors associated with late MI were presented with an acute coronary syndrome, whereas patients that underwent treatment with either PCI or CABG had less late MI (all p < 0.05). CONCLUSION: Among consecutive diabetic patients with MVD, at a median of 6-years CABG was associated with better survival and fewer non-fatal MI outcomes compared to PCI.

Equivalent outcomes after coronary artery bypass graft surgery performed by consultant versus trainee surgeons: A systematic review and meta-analysis.

OBJECTIVE: In recent years, concerns have been raised about the learning opportunities available to cardiac surgical trainees. This meta-analysis was conducted to assess the impact of trainee operator status on clinical outcomes after coronary artery bypass graft (CABG) surgery. METHODS: Medline, EMBASE, and the Cochrane Library were systematically searched for studies that reported CABG outcomes according to the training status of the primary operator (consultant vs trainee). Data were independently extracted by 2 investigators; a meta-analysis was conducted according to predefined clinical endpoints. RESULTS: Sixteen observational studies (n = 52,966) met criteria for inclusion, with 8 studies (n = 36,479) reporting propensity-adjusted analyses. Trainee cases were associated with increased aortic crossclamp duration (mean difference: 4.80; 95% confidence interval [CI], 0.76-8.83) and cardiopulmonary bypass duration (mean difference: 4.24; 95% CI, 0.00-8.47). Perioperative mortality was similar for CABG performed primarily by trainees versus consultants (odds ratio 0.98; 95% CI, 0.81-1.18). No significant difference was found in the incidence of perioperative stroke, myocardial infarction, acute renal failure, reoperation for bleeding, or wound infection. Trainee operator status was not associated with increased midterm mortality (hazard ratio 1.00; 95% CI, 0.90-1.11). In subgroup analysis that included 5 studies and 8025 patients, off-pump CABG trainee cases were not associated with increased perioperative mortality or morbidity. CONCLUSIONS: With appropriate supervision, conventional CABG can be performed by trainee surgeons without an adverse impact on perioperative outcomes or midterm survival. Data regarding off-pump CABG are limited, and further research is warranted to ascertain the impact of trainee operator status on long-term outcomes after off-pump CABG.

Aortic valve prosthesis-patient mismatch and long-term outcomes: 19-year single-center experience.

BACKGROUND: The clinical effects of prosthesis-patient mismatch (PPM) after aortic valve replacement, with respect to morbidity and survival, remain controversial, particularly in high-risk patient subgroups. METHODS: Patients undergoing aortic valve replacement from January 1992 to December 2010 were classified according to effective orifice area index into severe PPM (effective orifice area index<0.65 cm²/m²), moderate PPM (effective orifice area index 0.65 to 0.85 cm²/m²), and absent PPM (effective orifice area index>0.85 cm²/m²). Analyses examined major morbidity and total all-cause death. RESULTS: Prosthesis-patient mismatch was classified as severe (92 of 1,060; 8.7%), moderate (440 of 1,060; 41.5%), or absent (528 of 1,060; 49.8%). Moderate and severe PPM were unrelated to in-hospital morbidity or mortality. There were 440 deaths (41.5%) at 5.6 years median follow-up (interquartile range, 2.9 to 9.1). Trend toward poorer survival according to PPM group (χ2=5.46; p=0.07) was attenuated further with covariate adjustment. Sensitivity analyses demonstrated discrete mortality effects for moderate PPM in association with concomitant coronary artery bypass grafting, impaired left ventricular function, and older age (significant hazard ratios range, 1.05 to 1.57). Severe PPM also increased mortality risk in association with older age, concomitant coronary artery bypass grafting, and New York Heart Association Class III or IV (significant hazard ratios range, 1.06 to 2.65). CONCLUSIONS: Prosthesis-patient mismatch was not associated with mortality in covariate-adjusted models. However, a discrete mortality risk was attributable to moderate and severe PPM in patients of older age, or those with left ventricular dysfunction, New York Heart Association class III or IV, and concomitant coronary artery bypass grafting.