The long-term outcomes and durability of the Cox-Maze IV procedure for atrial fibrillation.

OBJECTIVE: Surgical ablation of atrial fibrillation (AF) is indicated both in patients with AF undergoing concomitant cardiac surgery and in those who have not responded to medical and/or catheter-based ablation therapy. This study examined our long-term outcomes following the Cox-Maze IV procedure (CMP-IV). METHODS: Between May 2003 and March 2018, 853 patients underwent either biatrial CMP-IV (n = 765) or a left-sided CMP-IV (n = 88) lesion set with complete isolation of the posterior left atrium. Freedom from atrial tachyarrhythmia (ATA) was assessed for up to 10 years. Rhythm outcomes were compared in multiple subgroups. Predictors of recurrence were determined using Fine-Gray regression, allowing for death as the competing risk. RESULTS: The majority of patients (513/853, 60%) had nonparoxysmal AF. Twenty-four percent of patients (201/853) had not responded to at least 1 catheter-based ablation. Prolonged monitoring was used in 76% (647/853) of patients during their follow-up. Freedom from ATA was 92% (552/598), 84% (213/253), and 77% (67/87) at 1, 5, and 10 years, respectively. By competing risk analysis, incidence of first ATA recurrence was 11%, 23%, and 35% at 1, 5, and 10 years, respectively. On Fine-Gray regression, age, peripheral vascular disease, nonparoxysmal AF, left atrial size, early postoperative ATAs, and absence of sinus rhythm at discharge were the predictors of first ATA recurrence over 10 years of follow-up. CONCLUSIONS: The CMP-IV had an excellent long-term efficacy at maintaining sinus rhythm. At late follow-up, the results of the CMP-IV remained superior to those reported for catheter ablation and other forms of surgical ablation for AF. Age, left atrial size, and nonparoxysmal AF were the most relevant predictors of late recurrence.

Concomitant surgical ablation for atrial fibrillation is associated with increased risk of acute kidney injury but improved late survival.

BACKGROUND: Acute kidney injury (AKI) after cardiac surgery remains a common complication that has been associated with increased morbidity and mortality. This study implemented Kidney Disease Improving Global Outcomes criteria to evaluate renal outcomes after concomitant surgical ablation for atrial fibrillation. METHODS: Patients with a history of atrial fibrillation who underwent elective cardiac surgery at our institution from 2008 to 2018 were retrospectively reviewed. Those with preoperative renal dysfunction were excluded. Patients were classified as those who underwent concomitant Cox-Maze IV (CMP-IV) (n = 376) or no surgical ablation (n = 498). Nearest neighbor 1:1 propensity matching was conducted on fourteen covariates. AKI was evaluated by mixed effects logistic regression analysis. Long-term survival was evaluated by proportional hazards regression. RESULTS: Propensity matching yielded 308 patients in each group (n = 616). All preoperative variables were similar between groups. The concomitant CMP-IV group had a greater incidence of AKI: 32% (n = 99) versus 16% (n = 49), P < .001. After accounting for bypass time and nonablation operations on mixed effects analysis, concomitant CMP-IV was associated with increased risk of AKI (odds ratio, 1.89; confidence interval, 1.12-3.18; P = .017). While AKI was associated with decreased late survival (P < .001), patients who received a concomitant CMP-IV maintained superior 7-year survival to patients who received no ablation (P < .001). No patients required permanent dialysis. CONCLUSIONS: Concomitant CMP-IV was independently associated with increased risk of AKI in the acute postoperative period. However, the long-term risks of AKI were offset by the significant survival benefit of CMP-IV. Concerns regarding new-onset renal dysfunction should not prohibit recommendation of this procedure in appropriate patients.

Late results after stand-alone surgical ablation for atrial fibrillation.

OBJECTIVES: Stand-alone surgical ablation of atrial fibrillation is indicated in patients with refractory atrial fibrillation who have failed medical or catheter-based ablation. Few reports of late outcomes after stand-alone surgical ablation exist using comprehensive follow-up with strict definitions of success. This study examined our late outcomes of the stand-alone Cox-Maze IV procedure. METHODS: Between January 2003 and December 2019, 236 patients underwent a stand-alone Cox-Maze IV for refractory atrial fibrillation. Freedom from atrial tachyarrhythmias was assessed by electrocardiography, Holter, or pacemaker interrogation for up to 10 years, with a mean follow-up of 4.8 ± 3.5 years. Rhythm outcomes were compared in multiple subgroups. Factors associated with recurrence were determined using Fine-Gray regression, allowing for death as the competing risk. RESULTS: The majority of patients (176/236, 75%) had nonparoxysmal atrial fibrillation. Median duration of preoperative atrial fibrillation was 6.2 years (interquartile range, 3-11). Fifty-nine percent of patients (140/236) failed 1 or more prior catheter-based ablation. Thirteen patients (6%) experienced a major complication. There was no 30-day mortality. Freedom from atrial tachyarrhythmias was 94% (187/199), 89% (81/91), and 77% (24/31) at 1, 5, and 10 years, respectively. There was no difference in freedom from atrial tachyarrhythmias between patients with paroxysmal atrial fibrillation versus nonparoxysmal atrial fibrillation (P > .05) or those undergoing sternotomy versus a minimally invasive approach (P > .05). Increased left atrial size and number of catheter ablations were associated with late atrial fibrillation recurrence. For patients who experienced any atrial tachyarrhythmia recurrence, the median number of recurrences was 1.5 (1.0-3.0). CONCLUSIONS: The stand-alone Cox-Maze IV had excellent late efficacy at maintaining sinus rhythm in patients with symptomatic, refractory atrial fibrillation, with low morbidity and no mortality. The Cox-Maze IV, in contrast to catheter-based ablation, was equally effective in patients with paroxysmal and nonparoxysmal atrial fibrillation.

Impact of Obesity on Atrial Fibrillation Recurrence Following Stand-Alone Cox Maze IV Procedure.

OBJECTIVE: Obesity is a strong and independent factor for the development of atrial fibrillation (AF), and adversely impacts the success of catheter ablation procedures for AF. This study evaluated the impact of body mass index (BMI) on the outcomes following surgical ablation of AF. METHODS: Between 2003 and 2019, 236 patients underwent a stand-alone biatrial Cox maze IV procedure (CMP-IV) for refractory AF. Obesity was defined as BMI ≥30 kg/m2. Patients were divided into two groups: BMI <30 kg/m2 (n = 100) and BMI ≥30 kg/m2 (n = 136). Freedom from atrial tachyarrhythmia (ATA) was determined using electrocardiography, Holter, or pacemaker interrogation at 1 year and annually thereafter. Recurrence was defined as any documented ATA lasting ≥30 s. Predictors of recurrence were determined using multivariable logistic regression. Preoperative and procedural outcomes were compared between groups. RESULTS: Obese patients had a higher rate of diabetes (16% vs 7%, P = 0.044) and larger left atrial diameter (4.9 ± 1.1 cm vs 4.6 ± 1.0 cm, P = 0.021) when compared to non-obese patients. There was no difference in major complication rate between the groups (4% vs 7%, P = 0.389). There was no operative mortality in either group. During 4.1 ± 2.4 years of follow-up, there was no significant difference in freedom from ATA with or without antiarrhythmic drugs in obese patients when compared to the non-obese group (P > 0.05). Absence of sinus rhythm at discharge predicted AF recurrence up to 7 years postoperatively. CONCLUSIONS: As opposed to catheter ablation, obesity did not adversely impact the short and long-term outcomes of stand-alone surgical ablation with CMP-IV, and BMI was not a predictor of AF recurrence. Additionally, there was no significant increase in major complications in obese patients.

Efficacy of the stand-alone Cox-Maze IV procedure in patients with longstanding persistent atrial fibrillation.

INTRODUCTION: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, and results in significant morbidity and mortality. The Cox-Maze IV procedure (CMP-IV) has been shown to have excellent efficacy in returning patients to sinus rhythm, but there have been few reports of late follow-up in sizable cohorts of patients with longstanding persistent AF, the most difficult type of AF to treat. METHODS AND RESULTS: Between May 2003 and March 2020, 174 consecutive patients underwent a stand-alone CMP-IV for longstanding persistent AF. Rhythm outcome was assessed postoperatively for up to 10 years, primarily via prolonged monitoring (Holter monitor, pacemaker interrogation, or implantable loop recorder). Fine-Gray regression was used to investigate factors associated with atrial tachyarrhythmia (ATA) recurrence, with death as a competing risk. Median duration of preoperative AF was 7.8 years (interquartile range: 4.0-12.0 years), with 71% (124/174) having failed at least one prior catheter-based ablation. There were no 30-day mortalities. Freedom from ATAs was 94% (120/128), 83% (53/64), and 88% (35/40) at 1, 5, and 7 years, respectively. On regression analysis, preoperative AF duration and early postoperative ATAs were associated with late ATAs recurrence. CONCLUSION: Despite the majority of patients having a long-duration of preoperative AF and having failed at least one catheter-based ablation, the stand-alone CMP-IV had excellent late efficacy in patients with longstanding persistent AF, with low morbidity and no mortality. We recommend consideration of stand-alone CMP-IV for patients with longstanding persistent AF who have failed or are poor candidates for catheter ablation.

Building a Collaborative Culture: Focus on Psychological Safety and Error Reporting.

BACKGROUND: At a Midwestern academic medical center, we introduced a structured teamwork training program to cardiothoracic operating room members with a goal of greater than or equal to 90% reporting positive psychological safety after the program. METHODS: We conducted teamwork training over 3 months. We distributed confidential questionnaires before the training, and then at 6 months and 12 months after the training. The primary outcome was the percentage of respondents reporting good or excellent psychological safety. Surveys were also distributed at the end of each case. Secondary outcomes were medical errors reported. Comparisons between percentages were evaluated with chi-square test. We examined the turnover of nurses and surgical technologists. RESULTS: Positive psychological safety was reported by 57 of 73 (78.1%) at baseline and by 60 of 68 (88.2%) at 12 months (difference = 10.1%; 95% confidence interval, -2.4% to 23.4%; P = .122). On the daily survey, 93.9% (n = 2786 of 2987) of operating room team members strongly agreed with the statement "I felt comfortable speaking up with questions and concerns" during the last quarter of the study. Reported medical errors decreased from 7.44% (n = 78 of 1048) in the first 6 months of the study to 4.65% (n = 55 of 1184) in the second 6 months (difference = 2.79%; 95% confidence interval, 0.8% to 4.8%; P = .005). In 2015, 19 nurses of a pool of 40 (47.5%) left, followed by 7 (17.5%) in 2016 and 10 (25%) in 2017. CONCLUSIONS: Overall, the results of this study suggest that structured teamwork training in the cardiothoracic operating room environment has the potential to improve teamwork, psychological safety, and communication, and potentially also patient outcomes.

Impact of age on atrial fibrillation recurrence following surgical ablation.

OBJECTIVES: The incidence of atrial fibrillation (AF) in patients older than 75 years of age is expected to increase, and its treatment remains challenging. This study evaluated the impact of age on the outcomes of surgical ablation of AF. METHODS: A retrospective review was performed of patients who underwent the Cox-maze IV procedure at a single institution between 2005 and 2017. The patients were divided into a younger (age <75 years, n = 548) and an elderly cohort (age ≥75 years, n = 148). Rhythm outcomes were assessed at 1 year and annually thereafter. Predictors of first atrial tachyarrhythmia (ATA) recurrence were determined using Fine-Gray regression, allowing for death as the competing risk. RESULTS: The mean age of the elderly group was 78.5 ± 2.8 years. The majority of patients (423/696, 61%) had nonparoxysmal AF. The elderly patients had a lower body mass index (P < .001) and greater rates of hypertension (P = .011), previous myocardial infarction (P = .017), heart failure (P < .001), and preoperative pacemaker (P = .008). Postoperatively, the elderly group had a greater rate of overall major complications (23% vs 14%, P = .017) and 30-day mortality (6% vs 2%, P = .026). The percent freedom from ATAs and antiarrhythmic drugs was lower in the elderly patients at 3 (69% vs 82%, P = .030) and 4 years (65% vs 79%, P = .043). By competing risk analysis, the incidence of first ATA recurrence was greater in elderly patients (33% vs 20% at 5 years; Gray test, P = .005). On Fine-Gray regression adjusted for clinically relevant covariates, increasing age was identified as a predictor of ATAs recurrence (subdistribution hazard ratio, 1.03; 95% confidence interval, 1.02-1.05, P < .001). CONCLUSIONS: The efficacy of the Cox-maze IV procedure was worse in elderly patients; however, the majority of patients remained free of ATAs at 5 years. The lower success rate in these greater-risk patients should be considered when deciding to perform surgical ablation.

Massive Left Atrial Thrombus After a Left Atrial Surgical Ablation and Bioprosthetic Mitral Valve Replacement.

Variability exists regarding the timing and duration of anticoagulation after surgical ablation for atrial fibrillation and bioprosthetic mitral valve replacement (MVR). We report a case in which a patient developed a massive left atrial (LA) thrombus after MVR and left-sided radiofrequency ablation (LRFA). Despite acutely elevated gradients across the bioprosthetic valve, the patient remained asymptomatic and hemodynamically stable; thus, a multidisciplinary, patient-centered discussion was had and the patient was treated successfully with oral anticoagulation.

Impact of Surgical Experience on Operative Mortality After Reoperative Cardiac Surgery.

BACKGROUND: Learning curves and skill attrition with aging have been reported to impair outcomes in select surgical subspecialties, but their role in complex cardiac surgery remains unknown. METHODS: From 1986 to 2019, 2314 patients underwent reoperative cardiac surgery: coronary artery bypass grafting (n = 543), valve (n = 1527), or combined coronary artery bypass grafting and valve (n = 244). Thirty-four different surgeons in practice between 1 and 39 years were included. Standardized mortality ratio (observed-to-expected) was determined for all surgeons in each post-training year of experience. RESULTS: Risk-adjusted cumulative sum change-point analysis was used to define five distinct career phases: 0 to 4 years, 5 to 8 years, 9 to 17 years, 18 to 28 years, and 29 to 39 years. With 5 to 8 years and 18 to 28 years of experience, standardized mortality ratio was near unity (0.95 and 1.05, respectively) and lowest with 9 to 17 years of experience (0.78, P = .03). In the youngest experience group (0 to 4 years), observed and expected mortality were both highest, and standardized mortality ratio was elevated at 1.29, which approached statistical significance (P = .059). In the oldest experience group (29 to 39 years), expected mortality was low compared with most other groups but observed mortality increased, yielding a significantly elevated standardized mortality ratio at 1.53 (P = .032). CONCLUSIONS: Standardized mortality ratios with reoperative cardiac surgery were highest early and late in a surgeon's career and lowest in mid career. As surgeons gain experience, outcomes improve through the first two career decades, then stabilize in the third decade before declining in the fourth decade.

Radiation Exposure During Transcatheter Valve Replacement: What Cardiac Surgeons Need to Know.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) and transcatheter mitral valve replacement expose operators to radiation. These procedures differ primarily in whether they are performed via a transfemoral (TF) or an alternative access (AA) approach. This study compared operator radiation exposure during transcatheter valve implantation when performed via a TF vs an AA approach, when performed in a catheterization lab vs a hybrid operating room (OR), and investigated the potential benefit of disposable shielding. METHODS: Dosimeters were worn during TAVR-TF (n = 50) and TAVR-AA (n = 31) procedures by operators. All TAVR-AA procedures were performed in a hybrid OR and TF procedures were performed in either catheterization labs (n = 16) or a hybrid OR (n = 34). Disposable radiation shielding pads (RADPAD; Worldwide Innovations and Technologies, Inc, Kansas City) or a placebo were added in a randomized, blinded fashion. RESULTS: Team radiation exposure was higher after TAVR-AA vs TAVR-TF (median 15.1 mRad [interquartile range: IQR 8.6, 32.4] vs 5.5 mRad [IQR 2.4, 9.8], P < .001). TAVR-TF procedures required the same amount of fluoroscopy time regardless of where they were performed (20.3 ± 7.4 min in hybrid OR vs 19.0 ± 6.4 min in catheterization lab, P = .55). However, radiation exposure for TAVR-TF remained higher when performed in a hybrid OR (median 9.0 mRad [IQR 4.5, 11.9] vs 2.2 mRad [IQR 1.3, 2.8], P < .001). Radiation exposure was greatest for TAVR-AA (median 15.1 mRad [IQR 8.6, 32.4]). The use of RADPAD did not decrease radiation exposure (median 9.0 mRad [IQR 4.5, 14.7] vs 9.4 mRad [IQR 2.8, 19.5], P = .82). CONCLUSIONS: Procedures performed in the hybrid OR were associated with higher operator radiation exposure. In comparison with the TF approach, AA cases had the highest levels of operator radiation. This is particularly important in cases of transcatheter mitral valve replacement that can only be done via an AA approach. The use of disposable radiation shielding in this series did not attenuate operator radiation exposure. Radiation shielding within hybrid ORs should be scrutinized in an effort to remain on par with that found within catheterization labs.

Observed to expected 30-day mortality as a benchmark for transcatheter aortic valve replacement.

OBJECTIVE: The observed-to-expected 30-day mortality ratio (O:E ratio) is a standard metric by which transcatheter aortic valve replacement (TAVR) trials have been evaluated. Early TAVR trials consistently demonstrated O:E ratio less than 0.6 after TAVR when based on the Society for Thoracic Surgery Predicted Risk of Mortality (STS-PROM) for surgical aortic valve replacement. Recent published results from the Transcatheter Valve Therapy (TVT) Registry have demonstrated O:E ratios of 1.0. We evaluated our own O:E ratios for TAVR to investigate this discordance. METHODS: Data were collected prospectively for TAVR patients from 2008 through 2015 (N = 546) and were reviewed retrospectively. The observed mortality and STS-PROM were calculated to formulate O:E ratios and were compared over a variety of subgroups. RESULTS: Overall, the O:E ratio for 30-day mortality was 0.4 and significantly less than 1 (P < .001; 95% confidence interval, 0.25-0.63). The O:E ratio relationship remained less than 0.5 for patients with low (STS-PROM < 4), moderate (STS-PROM = 4-8) and high risk (STS-PROM > 8). The O:E ratio was significantly higher for transapical patients (O:E ratio = 0.8) when compared with transfemoral patients (O:E ratio = 0.2). Lastly, O:E ratios for both commercial (O:E ratio = 0.5) and research (O:E ratio = 0.3) patients were similar (P = .337), and both were significantly less than 1 (P = .007 and P < .001, respectively). CONCLUSIONS: The STS-PROM consistently overestimated 30-day mortality after TAVR. Achieving an O:E ratio less than 0.6 may be a realistic goal for all TAVR programs. While an accurate and specific risk calculator for 30-day mortality after TAVR remains to be established, our data suggest that current TVT results are not acceptable for commercial TAVR and that programs with an O:E ratio greater than 0.6, based on the STS-PROM, should reevaluate internal processes to improve their results.

Anesthetic Considerations for the Transcatheter Management of Mitral Valve Disease.

The development of transcatheter interventions to provide a minimally invasive alternative to open surgical repair has revolutionized the care of patients with valvular heart disease. Recently, this technology has been expanded to allow for the treatment of pathology of the mitral valve. This review discusses the anesthetic considerations for patients presenting for transcatheter management of mitral valve disease, including transcatheter mitral valve replacement (TMVR) and transcatheter mitral valve repair (TMVRep). The initial focus is on the current literature on transcatheter interventions for mitral valve pathologies as well as current and developing technology for TMVR and TMVRep. The authors' institutional experience with anesthetic management for the TMVR and TMVRep procedures is described, including potential pitfalls and complications, concluding with a discussion of the role of transesophageal echocardiography in the care of this patient population.

Transcatheter Aortic Valve Replacement: Alternative Access beyond the Femoral Arterial Approach.

Aortic stenosis is the most prevalent valvular cardiovascular disease affecting the population over the age of 65 years. Transcatheter aortic valve replacement (TAVR) was developed as a minimally invasive surgical intervention to treat aortic stenosis in patients at high risk for surgical complications. Although the most commonly used approach for placement of a transcatheter aortic valve is in retrograde fashion via a transfemoral approach, narrowed luminal diameters, extensive atherosclerotic disease, or significant tortuosity may limit use of this route. In these patients, alternative methods including subclavian, transaortic, and transapical approaches should be considered. An understanding of these access routes and their respective indications and contraindications allows the radiologist to provide additional preprocedure measurements and images to help guide placement of the valve. ©RSNA, 2018.

Outcomes After the MitraClip Procedure in Patients at Very High Risk for Conventional Mitral Valve Surgery.

OBJECTIVE: Approximately 50% of patients with severe symptomatic mitral regurgitation are deemed too high risk for surgery. The MitraClip procedure is a viable option for this population. Our goal was to assess outcomes and survival of patients who underwent the MitraClip procedure at an institution where mitral valve surgery is routinely performed. METHODS: A retrospective study of patients undergoing the MitraClip procedure was performed. Baseline characteristics, perioperative outcomes, and follow-up echocardiographic and clinical outcomes were examined. Primary end point was survival. Secondary end points included technical failure (residual 3/4+ mitral regurgitation), reoperation, New York Heart Association symptoms, 30-day mortality, and other clinical outcomes. Predictors of mortality were determined using multivariable regression analysis. RESULTS: Fifty consecutive patients underwent the MitraClip procedure during the 4-year period. The average age was 83, the Society of Thoracic Surgeons predicted risk of mortality mean was 9.4%, 88% (44/50) had New York Heart Association III/IV symptoms, 86% (43/50) had 4+ mitral regurgitation, and 72% (36/50) had degenerative mitral disease etiology. Echocardiographic data (median [interquartile range] follow-up = 43 [26-392]) showed that 86% (43/50) of patients had 2+ or less mitral regurgitation. Sixty percent (24/40) had New York Heart Association I/II symptoms at last follow-up. Predictors of mortality were higher Society of Thoracic Surgeons predicted risk of mortality (P = 0.042, hazard ratio = 1.098) and previous cardiac surgery (P = 0.013, hazard ratio = 3.848). Survival at 1 and 2 years was 75% and 63%, respectively. CONCLUSIONS: Many patients with mitral valve regurgitation who are high risk for open surgery can be treated with the MitraClip procedure. In our study, most patients (86%) had a technically successful operation and postoperative outcomes including survival were acceptable.

Long-Term Survival Prediction for Coronary Artery Bypass Grafting: Validation of the ASCERT Model Compared With The Society of Thoracic Surgeons Predicted Risk of Mortality.

BACKGROUND: The recently developed American College of Cardiology Foundation-Society of Thoracic Surgeons (STS) Collaboration on the Comparative Effectiveness of Revascularization Strategy (ASCERT) Long-Term Survival Probability Calculator is a valuable addition to existing short-term risk-prediction tools for cardiac surgical procedures but has yet to be externally validated. METHODS: Institutional data of 654 patients aged 65 years or older undergoing isolated coronary artery bypass grafting between 2005 and 2010 were reviewed. Predicted survival probabilities were calculated using the ASCERT model. Survival data were collected using the Social Security Death Index and institutional medical records. Model calibration and discrimination were assessed for the overall sample and for risk-stratified subgroups based on (1) ASCERT 7-year survival probability and (2) the predicted risk of mortality (PROM) from the STS Short-Term Risk Calculator. Logistic regression analysis was performed to evaluate additional perioperative variables contributing to death. RESULTS: Overall survival was 92.1% (569 of 597) at 1 year and 50.5% (164 of 325) at 7 years. Calibration assessment found no significant differences between predicted and actual survival curves for the overall sample or for the risk-stratified subgroups, whether stratified by predicted 7-year survival or by PROM. Discriminative performance was comparable between the ASCERT and PROM models for 7-year survival prediction (p < 0.001 for both; C-statistic = 0.815 for ASCERT and 0.781 for PROM). Prolonged ventilation, stroke, and hospital length of stay were also predictive of long-term death. CONCLUSIONS: The ASCERT survival probability calculator was externally validated for prediction of long-term survival after coronary artery bypass grafting in all risk groups. The widely used STS PROM performed comparably as a predictor of long-term survival. Both tools provide important information for preoperative decision making and patient counseling about potential outcomes after coronary artery bypass grafting.