ABSTRACT
Objective: To investigate the effect of minimally invasive cardiac surgery (MICS) on resource utilization, cost, and postoperative outcomes in patients undergoing left-heart valve operations. Methods: Data were retrospectively reviewed for patients undergoing single-valve surgery (eg, aortic valve replacement, mitral valve replacement, or mitral valve repair) at a single center from 2018 to 2021, stratified by surgical approach: MICS vs full sternotomy (FS). Baseline characteristics and postoperative outcomes were compared. Primary outcome was high resource utilization, defined as direct procedure cost higher than the third quartile or either postoperative LOS ≥7 days or 30-day readmission. Secondary outcomes were direct cost, length of stay, 30-day readmission, in-hospital and 30-day mortality, and major morbidity. Multiple regression analysis was conducted, controlling for baseline characteristics, operative approach, valve operation, and lead surgeon to assess high resource utilization. Results: MICS was correlated with a significantly lower rate of high resource utilization (MICS, 31.25% [n = 115] vs FS 61.29% [n = 76]; P < .001). Median postoperative length of stay (MICS, 4 days [range, 3-6 days] vs FS, 6 days [range, 4 to 9 days]; P < .001) and direct cost (MICS, $22,900 [$19,500-$28,600] vs FS, $31,900 [$25,900-$50,000]; P < .001) were lower in the MICS group. FS patients were more likely to experience postoperative atrial fibrillation (P = .040) and renal failure (P = .027). Other outcomes did not differ between groups. Controlling for stratified Society of Thoracic Surgeons predicted risk of mortality, cardiac valve operation, and lead surgeon, FS demonstrated increased likelihood of high resource utilization (P < .001). Conclusions: MICS for left-heart valve pathology demonstrated improved postoperative outcomes and resource utilization.
ABSTRACT
D-type cyclins are central regulators of the cell division cycle and are among the most frequently deregulated therapeutic targets in human cancer1, but the mechanisms that regulate their turnover are still being debated2,3. Here, by combining biochemical and genetics studies in somatic cells, we identify CRL4AMBRA1 (also known as CRL4DCAF3) as the ubiquitin ligase that targets all three D-type cyclins for degradation. During development, loss of Ambra1 induces the accumulation of D-type cyclins and retinoblastoma (RB) hyperphosphorylation and hyperproliferation, and results in defects of the nervous system that are reduced by treating pregnant mice with the FDA-approved CDK4 and CDK6 (CDK4/6) inhibitor abemaciclib. Moreover, AMBRA1 acts as a tumour suppressor in mouse models and low AMBRA1 mRNA levels are predictive of poor survival in cancer patients. Cancer hotspot mutations in D-type cyclins abrogate their binding to AMBRA1 and induce their stabilization. Finally, a whole-genome, CRISPR-Cas9 screen identified AMBRA1 as a regulator of the response to CDK4/6 inhibition. Loss of AMBRA1 reduces sensitivity to CDK4/6 inhibitors by promoting the formation of complexes of D-type cyclins with CDK2. Collectively, our results reveal the molecular mechanism that controls the stability of D-type cyclins during cell-cycle progression, in development and in human cancer, and implicate AMBRA1 as a critical regulator of the RB pathway.
