Graciela Pritchard

Association of operative risk with the outcome of concomitant Cox Maze procedure: A comparison of results across risk groups

OBJECTIVES Cardiac surgery patients with atrial fibrillation face increased risks for perioperative morbidity and decreased survival, yet only 39% of patients presenting with atrial fibrillation undergo concomitant surgical ablation. This low percentage may relate to the perception of lower yield for surgical ablation, especially in patients with complex clinical presentations. In this study, we compared outcomes after a concomitant Cox maze III/IV procedure in patients with high, intermediate, and low predicted operative risk. METHODS Outcome data were prospectively captured after surgery. The additive European System for Cardiac Operative Risk Evaluation (EuroSCORE) was greater than 6 for high-risk patients (n = 145), 3 or less for low-risk patients (n = 76), and greater than 3 and 6 or less for intermediate-risk patients (n = 149). RESULTS No differences were found for perioperative morbidities, including operative mortality (high vs low risk, 2% vs 1%, P = 1.00; high vs intermediate risk, 2% vs 0.7%, P = .37). Median length of stay was longer in high-risk patients versus low-risk patients (8 vs 5 days, P < .001) and intermediate-risk patients (8 vs 6 days, P < .001). Return to sinus rhythm was comparable for high-risk versus low- and intermediate-risk patients at 6, 12, and 24 months. Physical health-related quality of life scores improved similarly for all groups at 12 months. No difference in long-term survival was found (log rank = 0.40; P = .82). CONCLUSIONS The Cox maze III/IV procedure can be performed safely and effectively in patients with higher operative risk, who fare well when compared with lower-risk patients. The Cox maze III/IV procedure should be considered carefully in patients with a significant history of atrial fibrillation.

Effect of patient age on blood product transfusion after cardiac surgery.

OBJECTIVE Blood product transfusion after cardiac surgery is associated with increased morbidity and mortality. Transfusion thresholds are often lower for the elderly, despite the lack of clinical evidence for this practice. This study examined the role of age as a predictor for blood transfusion. METHODS A total of 1898 patients were identified who had nonemergent cardiac surgery, between January 2007 and August 2013, without intra-aortic balloon pumps or reoperations, and with short (<24 hours) intensive care unit stays (age ≥75 years; n = 239). Patients age ≥75 years were propensity-score matched to those age <75 years to balance covariates, resulting in 222 patients per group. Analyses of the matched sample examined age as a continuous variable, scaled in 5-year increments. RESULTS After matching, covariates were balanced between older and younger patients. Older age significantly predicted postoperative (odds ratio = 1.39, P = .028), but not intraoperative (odds ratio = 0.96, P = .559), blood transfusion. Older age predicted longer length of stay (B = 0.21, P < .001), even after adjustment for blood product transfusion (B = 0.20, P < .001). As expected, older age was a significant predictor for poorer survival, even with multivariate adjustment (hazard ratio = 1.34, P = .042). CONCLUSIONS In patients with a routine postoperative course, older age was associated with more postoperative blood transfusion. Older age was also predictive of longer length of stay and poorer survival, even after accounting for clinical factors. Continued study into effects of transfusion, particularly in the elderly, should be directed toward hospital transfusion protocols to optimize perioperative care.

Rhythm course over 5 years following surgical ablation for atrial fibrillation

OBJECTIVES Reporting methods for surgical ablation (SA) of atrial fibrillation (AF) were standardized by the Heart Rhythm Society Guidelines, stating that results should be reported only for the first 2 years following SA. The purpose of this study was to assess the outcome of SA over 5 years and determine predictors for success over that period. METHODS Data were collected prospectively for all SA (n=787). Rhythm was verified by electrocardiogram and Holter monitoring at 3, 6, 9, 12, 18 and 24 months and yearly thereafter. Patients with rhythm status available at 2 and 5 years were included in the main analyses (n=137). Multivariate logistic regression was used for predictors of normal sinus rhythm (NSR). Receiver operating curves compared 2- and 5-year predicted probability against observed rhythm status by year. RESULTS Return to NSR at 2 years was 88% (80% off antiarrhythmic drugs) and at 5 years was 85% (71% off antiarrhythmic drugs). The majority of patients (64%) had stable NSR over 5 years. The only predictor for 2-year NSR was smaller left atrial size (odds ratio [OR]=0.40, P=0.044). Predictors for 5-year NSR were smaller left atrial size (OR=0.28, P=0.002), age (OR=0.91, P=0.031) and length of hospital stay (OR=0.85, P=0.026). CONCLUSIONS This study demonstrated stable results of SA for AF over time with somewhat different predictors for 2- and 5-year NSR in a group of patients with complete follow-up at both time points. Accurate models to determine predictors for success of SA more than 2 years after surgery are essential to better understand long-term outcome for patients with AF.

Amiodarone after surgical ablation for atrial fibrillation: Is it really necessary? A prospective randomized controlled trial.

OBJECTIVE Prophylactic antiarrhythmic drug (AAD) treatment is a well-established practice after catheter ablation for atrial fibrillation (AF), but it is controversial after surgical ablation. This prospective randomized controlled trial examined whether amiodarone after surgical ablation reduced atrial arrhythmia recurrence within the first 3 months after surgery. METHODS Ninety patients were randomized to receive (n = 45) or not receive (n = 45) amiodarone after surgical ablation. Rhythm status was ascertained via clinical follow-up and 72-hour continuous monitoring at 6 and 12 weeks, using Heart Rhythm Society guidelines. Primary outcome was defined as atrial arrhythmia recurrence, cardioversion, ablation, or crossover from no-amiodarone to amiodarone as a result of atrial arrhythmia during follow-up. An intention-to-treat approach was used. RESULTS The 2 study groups were similar in traditional predictors for failure, including left atrium size (5.0 vs 5.1 cm, P = .734), median AF duration (23 vs 20 months, P = .513), and long-standing persistent AF (44% vs 33%, P = .280). The primary outcome occurred in 52% of the no-amiodarone group (23 of 44) and 19% of the amiodarone group (8 of 43; P = .001). Cumulative freedom from primary outcome was greater in the amiodarone group (81.4% vs 47.7%, P < .001). Amiodarone was discontinued in 18 patients randomized to amiodarone for side effects, bradycardia, or noncompliance. CONCLUSIONS Prophylactic amiodarone reduced early atrial arrhythmia recurrence. These results are consistent with catheter AF ablation findings and should inform recommendations for prophylactic class I/III AAD after surgical AF ablation, regardless of discharge rhythm status. As previously recommended, monitoring for side effects and amiodarone discontinuation by 3 months, for patients in sinus rhythm, is warranted. CLINICAL TRIAL REGISTRATION NCT01416935.

Preoperative Hematocrit as a Predictor of Perioperative Morbidities Following Nonemergent Coronary Artery Bypass Surgery

Preoperative hematocrit (HCT) has predicted inferior outcome following cardiac surgery. However, the potential for preoperative HCT to be a marker for sicker patients was not well explored. This study examined the impact of HCT on outcome following nonemergent coronary artery bypass grafting (CABG) and whether the association is modified by operative risk or intraoperative blood transfusion.

Potential Impact of Modifiable Clinical Variables on Length of Stay After First-Time Cardiac Surgery

BACKGROUND Recent financial challenges highlight the importance of accurate prediction of length of hospital stay (LOS). We assessed reliability of The Society of Thoracic Surgeons (STS) risk prediction for extended and shorter LOS and examined whether modifiable clinical variables are associated with LOS in first-time cardiac surgery patients. METHODS Isolated aortic valve, mitral valve, and coronary artery bypass graft surgery patients since 2008 were included (n = 3,472). Multivariate regression was used to evaluate nonmodifiable and potentially modifiable (preoperative hematocrit, hemoglobin A1c, body mass index, current smoker, major perioperative morbidity, and blood product transfusion) predictors of LOS in days. RESULTS Mean age was 63.9 ± 11.2 years, 76% were males, and mean STS mortality risk was 1.9% ± 3.2%. Median (interquartile range) LOS was 4 (3 to 6) days. Predicted STS risk was 6.2% ± 7.1% for extended LOS (>14 days) and 48.3% ± 20.2% for short LOS (<6 days). Extended LOS was observed in 5.2% of patients (observed versus expected, 0.84; p = 0.019). Observed short LOS was better than predicted (67.8%; observed versus expected, 1.40; p < 0.001). Inclusion of modifiable variables in the LOS prediction model was significant (p < 0.001). Significant modifiable predictors were lower hematocrit, higher hemoglobin A1c, major morbidity, and transfusion. Longer predicted LOS from the model correlated with longer actual LOS (rs = 0.63; p < 0.001). Applying the prediction equation from the model to a hypothetical average patient, predicted LOS was 4.6 days. CONCLUSIONS The STS risk model was reliably predictive of short and extended LOS but did not allow prediction of exact LOS in days. Accounting for potentially modifiable clinical variables, such as low hematocrit and blood transfusion, especially in elective patients, should lead to shorter LOS, higher satisfaction, and reduced financial burden.

Minimally invasive mitral valve surgery without aortic cross-clamping and with femoral cannulation is not associated with increased risk of stroke compared with traditional mitral valve surgery: a propensity score-matched analysis †

OBJECTIVES Open-heart surgery with fibrillatory arrest has been reported to be associated with an increased risk of stroke. We examined whether minimally invasive mitral valve surgery with fibrillatory arrest conferred a higher risk of stroke/transient ischaemic attack (TIA) and other major complications compared with median sternotomy and cardioplegic arrest. METHODS Data were collected prospectively for 387 patients who had mitral valve surgery; 239 had a minimally invasive surgical approach and 148 had median sternotomy. All minimally invasive surgeries were performed by surgeons who were experienced in minimally invasive techniques. The effect of operative approach on risk of stroke/TIA and major morbidity was examined. After propensity score matching (PSM) was conducted between the two groups, 76 patients remained in each group. RESULTS Before matching, the incidence of stroke/TIA did not differ between patients who had minimally invasive surgery (0.5%, n = 1) and those who had median sternotomy (1.4%, n = 2; P = 0.56). Patients who had minimally invasive surgery had a lower incidence of other major morbidity (0.8%, n = 2) than patients who had median sternotomy (6.1%, n = 9; P = 0.004). After adjustment for age and Society of Thoracic Surgeons predicted risk, there was no effect of operative approach on the odds for stroke/TIA (odds ratio [OR] = 0.41, P = 0.49) or other major morbidity (OR = 0.40, P = 0.31). After PSM, patients were balanced on preoperative characteristics. No patient in either matched group experienced permanent stroke/TIA, and major morbidity did not differ between the two groups (minimally invasive, 1.3%, n = 1; median sternotomy, 1.3%, n = 1; P > 0.99). CONCLUSIONS A minimally invasive approach for mitral valve surgery on a fibrillating heart was not associated with a greater incidence of stroke/TIA than was median sternotomy. When performed by highly experienced surgeons, the minimally invasive approach with fibrillatory arrest did not increase the risk of perioperative stroke.

Minimally Invasive Fibrillating Heart Surgery: A Safe and Effective Approach for Mitral Valve and Surgical Ablation for Atrial Fibrillation

BACKGROUND Minimally invasive (MI) approaches to mitral valve surgery (MVS) and surgical ablation for atrial fibrillation (AF) are now performed routinely, and avoidance of aortic manipulation and cardioplegic arrest may further simplify the procedure. We present our experience with MI fibrillatory cardiac operations without aortic cross-clamping for MVS and AF ablation. METHODS Between January 2007 and August 2012, 292 consecutive patients underwent MVS (n = 177), surgical ablation (n = 81), or both (n= 34), with fibrillating heart through a right minithoracotomy. Baseline characteristics, perioperative outcomes, and long-term survival were evaluated. RESULTS The mean age was 56.8 years (range, 20-83 years). Reoperations were performed in 25 patients (9%). The overall MV repair rate was 93.4% (198/211), including 13.1% (26/198) with anterior leaflet repair. Repair was performed in 100% of patients with myxomatous MV disease. Of isolated posterior mitral valve repairs, 60.5% underwent repair with neochords (W.L. Gore and Associates, Flagstaff, AZ), and 29.7% underwent triangular resection. There was 1 operative mortality (0.3%), no intraoperative conversions to sternotomy, 4 reoperations (1.4%), 1 stroke (0.3%), and 1 transient ischemic attack (0.3%). The 12-month return to sinus rhythm was 93%, and sinus rhythm without class I and class III antiarrhythmic medication was 85%. One- and 2-year cumulative survival was 98.5% and 97.8%, respectively. At mean follow-up of 27.3 months, our outcomes compared favorably with the 2011 Society of Thoracic Surgeons (STS) nationally reported outcomes. CONCLUSIONS We demonstrated that low operative mortality and low stroke rate with MI fibrillating cardiac operations without cross-clamping allows for MVS and AF ablation. Our results suggest that the MI fibrillating heart approach is safe and effective.

Practice changes in blood glucose management following open heart surgery: from a prospective randomized study to everyday practice.

OBJECTIVES Targeted blood glucose (BG) levels following cardiac surgery continues to be debated. According to the Society of Thoracic Surgeons (STS) guidelines, BG should be kept <180 mg/dl following cardiac surgery. However, our practice and others shifted to a stricter BG control (90-110 mg/dl) based on data suggesting an association with improved outcome. Recently, we conducted a randomized control study that demonstrated no added value to stricter control over liberal control (120-180 mg/dl). As a result, we shifted our management accordingly. The purpose of this study was to evaluate the impact that this change to a more liberal BG management (BGM) had on patient outcomes at our centre. METHODS BGM was changed in June 2011 from strict (90-110 mg/dl) to liberal (120-180 mg/dl). Insulin drips, managed through a computerized algorithm, controlled BG for the first 72 h post surgery. Consecutive cardiac surgery patients operated on throughout 1 year prior to BGM change (n = 934) were propensity score matched to patients operated on throughout 1 year after the change (n = 927). RESULTS After matching, there were 846 patient pairs. There was no difference between cohorts for length of stay and perioperative complications, and both cohorts achieved acceptable outcomes. Incidence of perioperative renal failure (P = 0.02) and renal failure requiring dialysis (P = 0.004) were better for the cohort with liberal BGM. One-year cumulative survival did not differ between cohorts (log-rank = 0.70, P = 0.40). CONCLUSIONS Implementation of glycaemic control of 120-180 mg/dl into clinical practice was not associated with increased morbidity. The present results confirm our prior findings that a more liberal glycaemic control strategy to maintain BG is equal to a stricter target range. These findings are important for patient care and demonstrate the safety and efficacy of practice change for all patients following a successful randomized controlled trial.

A single center's experience with pacemaker implantation after the Cox maze procedure for atrial fibrillation

Objective: The Cox maze procedure (CM) is safe and effective for all atrial fibrillation (AF) types. A recent randomized trial found alarming rates of pacemaker implantation (PMI) during hospitalization after CM. The purpose of this study was to assess the rate of PMI and its impact on outcomes after CM. Methods: Incidence of PMI was captured for all CM patients (2005–2015; N = 739). Data were collected prospectively. Multivariable logistic regression was conducted to determine risk factors for PMI. Propensity score matching was conducted between concomitant CM patients and patients without surgical ablation since 2011. Results: Fifty‐two patients (7.0%) had in‐hospital PMI after CM. Most common primary indication for PMI was sick sinus syndrome (67%), followed by complete heart block (23%) and sinus bradycardia (10%). The only risk factor for in‐hospital PMI was type of procedure (P = .020). Patients with multiple valve procedures were at greatest risk (P = .004‐.035). STS‐defined perioperative outcomes were similar for patients with and without in‐hospital PMI. Sinus rhythm off antiarrhythmic drugs were similar by PMI. After propensity score matching (n = 180 per group), in‐hospital PMI was similar in CM patients and those without surgical ablation (5% vs 4%, P = .609). Conclusions: This study demonstrated lower incidence of PMI after CM procedures than recently reported. When indicated, PMI was not associated with increased short‐ or long‐term morbidity or inferior freedom from atrial arrhythmia. Efforts to increase surgeon training with the CM procedure and postoperative management awareness are warranted to improve rhythm outcome and minimize adverse events and PMI.