Con: epiaortic scanning is not routinely necessary for cardiac surgery

Impact of Aortic Atherosclerosis Burden on Outcomes of Surgical Aortic Valve Replacement

BACKGROUND

Epiaortic ultrasound detects and localizes ascending aortic atherosclerosis. In this analysis we investigated the association between epiaortic ultrasound-based atheroma grade during surgical aortic valve replacement (SAVR) and perioperative adverse outcomes.

METHODS

SAVR patients in a randomized trial of 2 embolic protection devices underwent a protocol-defined 5-view epiaortic ultrasound read at a core laboratory. Aortic atherosclerosis was quantified with the Katz atheroma grade, and patients were categorized as mild (grade I-II) or moderate/severe (grade III-V). Multivariable logistic regression was used to estimate associations between atheroma grade and adverse outcomes, including death, clinically apparent stroke, cerebral infarction on diffusion-weighted magnetic resonance imaging, delirium, and acute kidney injury (AKI) by 7 and 30 days.

RESULTS

Precannulation epiaortic ultrasound data were available for 326 of 383 randomized patients (85.1%). Of these, 106 (32.5%) had moderate/severe Katz atheroma grade at any segment of the ascending aorta. Although differences in the composite of death, stroke, or cerebral infarction on diffusion-weighted magnetic resonance imaging by 7 days were not statistically significant, moderate/severe atheroma grade was associated with a greater risk of AKI by 7 days (adjusted odds ratio, 2.63; 95% confidence interval, 1.24-5.58; P = .01). At 30 days, patients with moderate/severe atheroma grade had a greater risk of death, stroke, or AKI (adjusted odds ratio, 1.97; 95% confidence interval, 1.04-3.71; P = .04).

CONCLUSIONS

Moderate/severe aortic atherosclerosis was associated with an increased risk of adverse events after SAVR. Epiaortic ultrasound may serve as a useful adjunct for identifying patients who may benefit from strategies to reduce atheroembolic complications during SAVR.

From accuracy to patient outcome and cost-effectiveness evaluations of diagnostic tests and biomarkers: an exemplary modelling study

BACKGROUND

Proper evaluation of new diagnostic tests is required to reduce overutilization and to limit potential negative health effects and costs related to testing. A decision analytic modelling approach may be worthwhile when a diagnostic randomized controlled trial is not feasible. We demonstrate this by assessing the cost-effectiveness of modified transesophageal echocardiography (TEE) compared with manual palpation for the detection of atherosclerosis in the ascending aorta.

METHODS

Based on a previous diagnostic accuracy study, actual Dutch reimbursement data, and evidence from literature we developed a Markov decision analytic model. Cost-effectiveness of modified TEE was assessed for a life time horizon and a health care perspective. Prevalence rates of atherosclerosis were age-dependent and low as well as high rates were applied. Probabilistic sensitivity analysis was applied.

RESULTS

The model synthesized all available evidence on the risk of stroke in cardiac surgery patients. The modified TEE strategy consistently resulted in more adapted surgical procedures and, hence, a lower risk of stroke and a slightly higher number of life-years. With 10% prevalence of atherosclerosis the incremental cost-effectiveness ratio was € 4,651 and € 481 per quality-adjusted life year in 55-year-old men and women, respectively. In all patients aged 65 years or older the modified TEE strategy was cost saving and resulted in additional health benefits.

CONCLUSIONS

Decision analytic modelling to assess the cost-effectiveness of a new diagnostic test based on characteristics, costs and effects of the test itself and of the subsequent treatment options is both feasible and valuable. Our case study on modified TEE suggests that it may reduce the risk of stroke in cardiac surgery patients older than 55 years at acceptable cost-effectiveness levels.

Resolving the blind spot of transoesophageal echocardiography: a new diagnostic device for visualizing the ascending aorta in cardiac surgery

BACKGROUND

Atherosclerosis of the ascending aorta (AA) and stroke after cardiac surgery are related. Knowledge of the location of AA-atherosclerosis pre-sternotomy allows changes in surgical strategy to avoid manipulation of the AA. The gold-standard for assessment of AA-atherosclerosis is intraoperative epiaortic ultrasound scanning (EUS). Transoesophageal echocardiography (TOE) is unable to detect atherosclerosis in the distal AA due to the 'blind spot'. A new method [A-View (Aortic-view) method] using a fluid-filled catheter may enhance the assessment of distal AA-atherosclerosis. The aim of this study was to evaluate whether the A-View method indeed visualizes the distal AA and to assess the safety of this technology.

METHODS

In a cross-sectional diagnostic study, 41 patients undergoing cardiac surgery including sternotomy underwent the same work-up including TOE, the A-View method, EUS, and routine operative monitoring.

RESULTS

With the A-View method, the distal AA was visible in all (100%) patients. There were no clinical important side-effects associated with the use of the A-View catheter; however, in one patient the endotracheal tube was accidentally dislocated leading to a decrease in Sa(O2). Severity of atherosclerosis visualized with the A-View method compared with EUS results showed good agreement between the two methods [Kappa of 0.69 (0.50-0.88)]. The Bland-Altman analysis showed poor agreement in plaque-size measurements (bias 0.05 cm2, limits of agreement - 0.63 to 0.74 cm2).

CONCLUSIONS

The A-View method offers a minimally invasive and safe approach to preoperatively resolving the blind spot of TOE. Compared with EUS, the A-View method yielded satisfactory results in the detection of AA-atherosclerosis. The A-View method seems a promising tool for patients undergoing cardiac surgery to direct surgical management.

Propensity case-matched analysis of off-pump coronary artery bypass grafting in patients with atheromatous aortic disease

OBJECTIVE

Atheromatous aortic disease is a risk factor for excessive mortality and stroke in patients undergoing coronary artery bypass grafting. Outcomes of off-pump coronary artery bypass grafting and coronary artery bypass grafting with cardiopulmonary bypass in patients with severe atheromatous aortic disease were compared by propensity case-match methods.

METHODS

Routine intraoperative transesophageal echocardiography identified 985 patients undergoing isolated coronary artery bypass grafting with severe atheromatous disease in the aortic arch or ascending aorta. Off-pump coronary artery bypass grafting was performed in 281 patients (28.5%). Propensity matched-pairs analysis was used to match patients undergoing off-pump coronary artery bypass grafting (n = 245) with patients undergoing coronary artery bypass grafting with cardiopulmonary bypass.

RESULTS

Univariate analysis revealed decreased hospital mortality (16/245, 6.5% vs 28/245, 11.4%; P =.058) and stroke prevalence (4/245, 1.6% vs 14/245, 5.7%; P =.03) in off-pump coronary artery bypass grafting compared with coronary artery bypass grafting with cardiopulmonary bypass. Freedom from any postoperative complication was higher in off-pump coronary artery bypass grafting compared with coronary artery bypass grafting with cardiopulmonary bypass (226/245, 92.2% vs 196/245, 80.0%; P <.001). Multivariable analysis of preoperative risk factors showed that increased hospital mortality was associated with coronary artery bypass grafting with cardiopulmonary bypass (odds ratio = 2.7; P =.01), fewer grafts (P =.05), acute myocardial infarction (odds ratio = 11.5; P <.001), chronic obstructive pulmonary disease (odds ratio = 2.4; P =.03), previous cardiac surgery (odds ratio = 10.2, P =.05), and peripheral vascular disease (odds ratio = 2.1; P =.05). Cardiopulmonary bypass was the only independent risk factor for stroke (odds ratio = 3.6, P =.03). At 36 months' follow-up, comparable survival was observed in the off-pump coronary artery bypass grafting and coronary artery bypass grafting with cardiopulmonary bypass groups (74% vs 72%). Multivariable analysis revealed that renal disease (P <.001), advanced age (P <.001), previous myocardial infarction (P =.03), and lower number of grafts (P =.02) were independent risks for late mortality.

CONCLUSIONS

Patients with severe atherosclerotic aortic disease who undergo off-pump coronary artery bypass grafting have a significantly lower prevalence of hospital mortality, perioperative stroke, and overall complications than matched patients who underwent coronary artery bypass grafting with cardiopulmonary bypass. Routine intraoperative transesophageal echocardiography identifies severe atheromatous aortic disease and directs the choice of surgical technique.