The impact of hospital size on national trends and outcomes in isolated open proximal aortic surgery.

OBJECTIVE: To determine the impact of hospital size on national trend estimates of isolated open proximal aortic surgery for benchmarking hospital performance. METHODS: Patients age >18 years who underwent isolated open proximal aortic surgery for aneurysm and dissection from 2002 to 2014 were identified using the National Inpatient Sample. Concomitant valvular, vessel revascularization, re-do procedures, endovascular, and surgery for descending and thoracoabdominal aorta were excluded. Discharges were stratified by hospital size and analyzed using trend, multivariable regression, propensity-score matching analysis. RESULTS: Over a 13-year period, 53,657 isolated open proximal aortic operations were performed nationally. Although the total number of operations/year increased (∼2.9%/year increase) and overall in-hospital mortality decreased (∼4%/year; both P < .001 for trend), these did not differ by hospital size (P > .05). Large hospitals treated more sicker and older patients but had shorter length of stay and lower hospital costs (both P < .001). Even after propensity-score matching, large hospital continued to demonstrate superior in-hospital outcomes, although only statistically for major in-hospital cardiac complications compared with non-large hospitals. In our subgroup analysis of dissection versus non-dissection cohort, in-hospital mortality trends decreased only in the non-dissection cohort (P < .01) versus dissection cohort (P = .39), driven primarily by the impact of large hospitals (P < .01). CONCLUSIONS: This study demonstrates increasing volume and improving outcomes of isolated open proximal aortic surgeries nationally over the last decade regardless of hospital bed size. Moreover, the resource allocation of sicker patients to larger hospital resulted shorter length of stay and hospital costs, while maintaining similar operative mortality to small- and medium-sized hospitals.

Joint preoperative transthoracic and intraoperative transoesophageal echocardiographic assessment of functional mitral regurgitation severity provides better association with long-term mortality.

OBJECTIVES: Functional mitral regurgitation (MR) is observed with ischaemic heart disease or aortic valve disease. Assessing the value of mitral valve repair or replacement (MVR/P) is complicated by frequent discordance between preoperative transthoracic echocardiographic (pTTE) and intraoperative transoesophageal echocardiographic (iTOE) assessment of MR severity. We examined the association of pTTE and iTOE with postoperative mortality in patients with or without MR, at the time of coronary artery bypass grafting (CABG) and/or aortic valve replacement without MVR/P. METHODS: Medical records of 6629 patients undergoing CABG and/or aortic valve replacement surgery with or without functional MR and who did not undergo MVR/P were reviewed. MR severity assessed by pTTE and iTOE were examined for association with postoperative mortality using proportional hazards regression while accounting for patient and operative characteristics. RESULTS: In 72% of 709 patients with clinically significant (moderate or greater) functional MR detected by pTTE, iTOE performed after induction of anaesthesia demonstrated a reduction in MR severity, while 2% of patients had increased severity of MR by iTOE. iTOE assessment of MR was better associated with long-term postoperative mortality than pTTE in patients with moderate MR [hazard ratio (HR) 1.31 (1.11-1.55) vs 1.02 (0.89-1.17), P-value for comparison of HR 0.025] but was not different for more than moderate MR [1.43 (0.96-2.14) vs 1.27 (0.80-2.02)]. CONCLUSIONS: In patients undergoing CABG and/or aortic valve replacement without MVR/P, these findings support intraoperative reassessment of MR severity by iTOE as an adjunct to pTTE in the prediction of mortality. Alone, these findings do not yet provide evidence for an operative strategy.

Parsimonious assessment for reoperative aortic valve replacement; the deterrent effect of low left ventricular ejection fraction and renal impairment.

BACKGROUND: Patient comorbidities play a pivotal role in the surgical outcomes of reoperative aortic valve replacement (re-AVR). Low left ventricular ejection fraction (LVEF) and renal insufficiency (Cr >2 mg/dL) are known independent surgical risk factors. Improved preoperative risk assessment can help determine the best therapeutic approach. We hypothesize that re-AVR patients with low LVEF and concomitant renal insufficiency have a prohibitive surgical risk and may benefit from transcatheter AVR (TAVR). METHODS: From January 2002 to March 2013, we reviewed 232 patients who underwent isolated re-AVR. Patients older than 80 years were excluded to adjust for unobserved frailty. We identified 37 patients with a ≤35% LVEF (low ejection fraction group-LEF) and 195 patients with >35% LVEF (High ejection fraction group-HEF). RESULTS: The mean age was 68.4±11.5 years and there were more females (86.5% versus 64.1%, P=0.007) in the LEF group. The prevalence of renal insufficiency was higher in LEF patients (27% versus 5.6%, P=0.001). Higher operative mortality (13.5% versus 3.1%, P=0.018) was observed in the LEF group. Stroke rates were similar in both groups (8.1% versus 4.1%, P=0.39). Unadjusted cumulative survival was significantly lower in LEF patients (6.6 years, 95% CI: 5.2-8.0, versus 9.7 years, 95% CI: 8.9-10.4, P=0.024). In patients without renal insufficiency, LEF and HEF had similar survival (8.3 years, 95% CI: 7.1-9.5, versus 9.9 years, 95% CI: 9.1-10.6, P=0.90). Contrarily, in patients with renal insufficiency, LEF led to a significantly lower survival (1.1 years, 95% CI: 0.1-2.0, versus 4.8 years, 95% CI: 2.2-7.3, P=0.050). Adjusted survival analysis revealed elevations in baseline creatinine (HR =4.28, P<0.001) and LEF (HR =5.33, P=0.041) as significant predictors of long-term survival, with a significant interaction between these comorbidities (HR =7.28, P<0.001). CONCLUSIONS: In re-AVR patients, low LVEF (≤35%) is associated with increased operative mortality. Concomitant renal insufficiency in these patients results in a prohibitively low cumulative survival. These reoperative surgical outcomes should warrant expanding the role of TAVR for reoperative patients with LEF and renal impairment.

Mechanical versus bioprosthetic mitral valve replacement in patients <65 years old.

OBJECTIVE: Because of its durability, the mechanical valve is typically chosen for young patients undergoing mitral valve replacement (MVR). However, a bioprosthetic valve might have the benefit of valve-in-valve transcatheter valve replacement when valve failure occurs. We examined the outcomes in patients who had undergone mechanical valve MVR (MVRm) versus bioprosthetic valve MVR (MVRb) in patients aged <65 years. METHODS: A total of 768 consecutive patients aged <65 years, who had undergone MVR from January 1991 to June 2012 were identified. Propensity matching was used to derive a case-control subset for analysis. Long-term outcomes were collected by chart review, routine patient follow-up, and query of the Social Security Death Index. The postoperative and long-term outcomes of interest included combined stroke and embolic events, reoperations, and mortality. RESULTS: Of 768 consecutive patients, 627 were in the MVRm and 141 in the MVRb group. Propensity score matching yielded a cohort of 125 MVRb (89%) and 125 control MVRm patients with similar etiology mixes. The groups were similar in age (MVRm, 53.2 ± 9.0 years; MVRb, 53.8 ± 10.6 years; P = .617) and other preoperative characteristics. The postoperative outcomes were also similar between the 2 groups, including reoperation for bleeding, stroke, deep sternal infection, sepsis, and length of hospital stay. The operative mortality was also similar (MVRm, 5.6%; MVRb, 8.0%; P = .617). However, Kaplan-Meier analysis showed the MVRb group had a greater reoperation rate (P = .001) and shorter estimated survival (11.3 vs 13.5 years, P = .004). The incidence of bleeding and stroke or embolic events between the 2 groups was similar. CONCLUSIONS: In the present report, MVRb for patients <65 years old was associated with a high reoperation rate and decreased survival. Although a future transcatheter valve-in-valve technique for a failed bioprosthetic valve might reduce the risk of reoperation, this finding confirms the safety of mechanical valves in this group.

Minimally invasive aortic valve replacement in octogenarian, high-risk, transcatheter aortic valve implantation candidates.

OBJECTIVE: Risk-stratifying algorithms are currently used to determine which patients may be at prohibitive risk for surgical aortic valve replacement, and thus candidates for transcatheter aortic valve implantation. Minimally invasive surgical approaches have been successful in reducing morbidity and improving survival after aortic valve replacement, especially in octogenarians. We documented outcomes after minimally invasive aortic valve replacement in high-risk octogenarians who may be considered candidates for percutaneous/transapical aortic valve replacement. METHODS: From 1996 to 2009, minimally invasive aortic valve replacement was performed in 249 consecutive octogenarians. We used the modified European System for Cardiac Operative Risk Evaluation and Society of Thoracic Surgeons score to risk-stratify patients and characterize all early and late results. RESULTS: The mean age at operation was 84±3 (range 80-95) years, and 111 patients (45%) were male. Twenty-one percent (n=52) had previous cardiac surgery. Operative mortality was 3% (n=8/249). The median modified European System for Cardiac Operative Risk Evaluation (11%; interquartile range, 6-14) and Society of Thoracic Surgeons score (10.5%; interquartile range, 7-17) were not predictive of 30-day mortality in this cohort of patients (European System for Cardiac Operative Risk Evaluation c-index=0.527, P=.74, Society of Thoracic Surgeons score c-index=0.67, P=.18). Despite their poor predictive power, the Society of Thoracic Surgeons score and European System for Cardiac Operative Risk Evaluation were correlated with each other (r=0.40, P<.0001). Postoperative complications included stroke in 10 patients (4%), pneumonia in 3 patients (1%), renal failure requiring dialysis in 2 patients (1%), cardiac arrest in 2 patients (1%), pulmonary embolism in 1 patient (1%), and sepsis in 1 patient (1%). Follow-up was available for 238 patients (96%) and extended up to 12 years. Overall, long-term survival after minimally invasive aortic valve replacement at 1, 5, and 10 years was 93%, 77%, and 56%, respectively. There was no significant difference in long-term survival compared with that of a US age- and gender-matched population (standardized mortality ratio, 1.01; 95% confidence interval, 0.76-1.37; P=.88). A multivariate Cox-proportional hazards model indicated that increasing age (hazard ratio, 1.10; P=.008) and severe chronic obstructive pulmonary disease (hazard ratio, 2.52; P<.007) were significant predictors of survival. By using these factors, a clinical prediction model (P=.02) was developed and demonstrated that low-risk patients (first quartile prediction score) had 1-, 5-, and 8-year survival of 94%, 84%, and 67%, whereas high-risk patients (third quartile prediction score) had 1-, 5-, and 8-year survival of 89%, 74%, and 49%, respectively. CONCLUSIONS: Patients thought to be high-risk candidates for surgical aortic valve replacement have excellent outcomes after minimally invasive surgery with long-term survival that is no different than that of an age- and gender-matched US population. These data provide a benchmark against which outcomes of transcatheter aortic valve implantation could be compared.