Current risks of HeartMate II pump thrombosis: Non-parametric analysis of Interagency Registry for Mechanically Assisted Circulatory Support data.

BACKGROUND: Data from 3 institutions revealed an abrupt increase in HeartMate II (Thoratec) pump thrombosis starting in 2011, associated with 48% mortality at 6 months without transplantation or pump exchange. We sought to discover if the increase occurred nationwide in Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) data, and if so (1) determine if accelerated risk continued, (2) identify predictors, (3) investigate institutional variability, and (4) assess mortality after pump thrombosis. METHODS: From April 2008 to June 2014, 11,123 HeartMate II devices were implanted at 146 institutions. Machine learning, non-parametric Random Forests for Survival was used to explore risk-adjusted thrombosis based on 87 pre-implant and implant variables, including implant date. RESULTS: A total of 995 pumps thrombosed, with risk peaking within weeks of implant. The risk-adjusted increase in pump thrombosis began in 2010, reached a maximum in 2012, and then plateaued at a level that was 3.3-times higher than pre-2010. Pump exchange, younger age, and larger body mass index were important predictors, and institutional variability was largely explained by implant date, patient profile, and duration of support. The probability of death within 3 months after pump thrombosis was 24%. CONCLUSIONS: Accelerated risk of HeartMate II thrombosis was confirmed by Interagency Registry for Mechanically Assisted Circulatory Support data, with risk subsequently leveling at a risk-adjusted rate higher than observed pre-2010. This elevated thrombosis risk emphasizes the need for improved mechanical circulatory support systems and post-market surveillance of adverse events. Clinicians cognizant of these new data should incorporate them into their and their patients' expectations and understanding of risks relative to those of transplantation and continued medical therapy.

Atrial fibrillation complicating lung cancer resection.

OBJECTIVE: To (1) characterize atrial fibrillation complicating lung cancer resection, (2) evaluate its temporal relationship to other postoperative complications, and (3) assess its economics. METHODS: From January 1998 to August 2002, 604 patients underwent anatomic lung cancer resection. Atrial fibrillation prevalence, onset, and temporal associations with other postoperative complications were determined. Propensity matching was used to assess economics. RESULTS: Atrial fibrillation occurred in 113 patients (19%), peaking on postoperative day 2. Older age, male gender, heart failure, clamshell incision, and right pneumonectomy were risk factors (P < .01). Although atrial fibrillation was solitary in 75 patients (66%), other postoperative complications occurred in 38. Respiratory and infectious complications were temporally linked with atrial fibrillation onset. In 91 propensity-matched pairs, patients developing atrial fibrillation had more other postoperative complications (30% vs. 9%, P < .0004), had longer postoperative stays (median 8 vs 5 days, P < .0001), incurred higher costs (cost ratio 1.8, 68% confidence limits 1.6-2.1), and had higher in-hospital mortality (8% vs 0%, P = .01). Even when atrial fibrillation was a solitary complication, hospital stay was longer (median 7 vs 5 days, P < .0001), and cost was higher (cost ratio 1.5, 68% confidence limits 1.2-1.6). CONCLUSION: Atrial fibrillation occurs in 1 in 5 patients after lung cancer resection, with peak onset on postoperative day 2. Risk factors are both patient and procedure related, and atrial fibrillation may herald other serious complications. Although often solitary, atrial fibrillation is associated with longer hospital stay and higher cost. It therefore requires prompt treatment and should stimulate investigation for other problems.

Combined bronchoscopy, mediastinoscopy, and thoracotomy for lung cancer: who benefits?

OBJECTIVES: Surgical staging and resection of lung cancer may be done as 1 operation (combined) or 2 (staged). This study evaluates the safety and efficiency of these treatment strategies. METHODS: From 1998 to July 2001, 343 patients underwent bronchoscopy, mediastinoscopy, and thoracotomy without induction chemoradiotherapy by 3 surgeons. Fifty-seven patients were staged and 286 combined. Staged patients had higher clinical stage (P <.001). Propensity-matched groups were compared to adjust for this and other differences. Factors associated with safety and efficiency were identified by propensity-adjusted multivariable analysis. RESULTS: Mortality and morbidity were similar for both strategies. Efficiency, measured by shorter operative time (1.2 hours) and lower cost (25%), was better for combined strategy (P <.001). Hospital stay was similar, but revenue was 12% higher for the staged strategy (P <.001). In propensity-matched comparisons excluding surgeon, results were similar to the above. Comparisons including surgeon demonstrated similar cost and revenue for both strategies. Increased mortality and morbidity were associated only with patient and tumor characteristics: male gender, worsening Eastern Cooperative Oncology Group performance status, and increasing pathological node classification. All measures of efficiency worsened with increasing pathological classifications. Staged strategy was associated with increased operative time and revenue, while one surgeon and patient smoking history were associated with increased hospital stay and costs. CONCLUSIONS: The combined strategy provides efficient, safe health care for clinically operable lung cancer patients, but it may not be as financially rewarding as the staged strategy. Treatment strategy is only 1 of many determinants of efficiency.