Randomized Trial of Surgical Left Atrial Appendage Closure: Protection Against Cerebrovascular Events.

Following open-heart surgery, atrial fibrillation and stroke occur frequently. Left atrial appendage closure added to elective open-heart surgery could reduce the risk of ischemic stroke. We aim to examine if routine closure of the left atrial appendage in patients undergoing open-heart surgery provides long-term protection against cerebrovascular events independently of atrial fibrillation history, stroke risk, and oral anticoagulation use. Long-term follow-up of patients enrolled in the prospective, randomized, open-label, blinded evaluation trial entitled left atrial appendage closure by surgery (NCT02378116). Patients were stratified by oral anticoagulation status and randomized (1:1) to left atrial appendage closure in addition to elective open-heart surgery vs standard care. The primary composite endpoint was ischemic stroke events, transient ischemic attacks, and imaging findings of silent cerebral ischemic lesions. Two neurologists blinded for treatment assignment adjudicated cerebrovascular events. In total, 186 patients (82% males) were reviewed. At baseline, mean (standard deviation (SD)) age was68 (9) years and 13.4% (n = 25/186) had been diagnosed with atrial fibrillation. Median [interquartile range (IQR)] CHA2DS2-VASc was 3 [2,4] and 25.9% (n = 48/186) were receiving oral anticoagulants. Mean follow-up was 6.2 (2.5) years. The left atrial appendage closure group experienced fewer cerebrovascular events; intention-to-treat 11 vs 19 (P = 0.033, n = 186) and per-protocol 9 vs 17 (P = 0.186, n = 141). Left atrial appendage closure as an add-on open-heart surgery, regardless of pre-surgery atrial fibrillation and oral anticoagulation status, seems safe and may reduce cerebrovascular events in long-term follow-up. More extensive randomized clinical trials investigating left atrial appendage closure in patients without atrial fibrillation and high stroke risk are warranted.

New-onset of postoperative atrial fibrillation is likely to recur in the absence of other triggers.

BACKGROUND: Incident atrial fibrillation (AF) is reported in 10%-65% of patients without previous AF diagnosis after open heart surgery. The risk of late AF recurrence after a postoperative AF onset is unclear, and it is controversial whether AF limited to the postoperative period should elicit oral anticoagulation (OAC) therapy. The primary objective of this study was to evaluate the long-term recurrence of AF in patients developing new-onset peri-procedural AF. PATIENTS AND METHODS: Patients (n=189) with available baseline and follow-up data included in Left Atrial Appendage Closure with Surgery trial were coded for known AF at baseline and for postoperative first-time AF diagnosis. AF occurrence was classified as follows: peri-procedural ≤7 days postoperatively, early >7 days but ≤3 months and late >3 months. Patients with no AF recurrence registered during follow-up were invited to undergo Holter monitoring. RESULTS: A total of 163 (86.2%) patients had no history of AF. Among these, 80 (49.1%) developed new-onset peri-procedural AF. After a mean follow-up of 3.7±1.6 years, late AF occurred in 35 of the 80 (43.8%) patients who developed peri-procedural AF and in 6 additional patients (7.2%) who remained in sinus rhythm until discharge (hazard ratio [HR] 9.3, 95% CI 3.8-22.4, p<0.001). Patients with peri-procedural AF and early AF had 12.24 times higher risk of late AF (95% CI 4.76-31.45, p<0.001) as compared to the group with no postoperative AF. CONCLUSION: New-onset of AF after open heart surgery has a high rate of recurrence and should not be regarded as a self-limiting phenomenon secondary to surgery.

Adding left atrial appendage closure to open heart surgery provides protection from ischemic brain injury six years after surgery independently of atrial fibrillation history: the LAACS randomized study.

BACKGROUND: Open heart surgery is associated with high occurrence of atrial fibrillation (AF), subsequently increasing the risk of post-operative ischemic stroke. Concomitant with open heart surgery, a cardiac ablation procedure is commonly performed in patients with known AF, often followed by left atrial appendage closure with surgery (LAACS). However, the protective effect of LAACS on the risk of cerebral ischemia following cardiac surgery remains controversial. We have studied whether LAACS in addition to open heart surgery protects against post-operative ischemic brain injury regardless of a previous AF diagnosis. METHODS: One hundred eighty-seven patients scheduled for open heart surgery were enrolled in a prospective, open-label clinical trial and randomized to concomitant LAACS vs. standard care. Randomization was stratified by usage of oral anticoagulation (OAC) planned to last at least 3 months after surgery. The primary endpoint was a composite of post-operative symptomatic ischemic stroke, transient ischemic attack or imaging findings of silent cerebral ischemic (SCI) lesions. RESULTS: During a mean follow-up of 3.7 years, 14 (16%) primary events occurred among patients receiving standard surgery vs. 5 (5%) in the group randomized to additional LAACS (hazard ratio 0.3; 95% CI: 0.1-0.8, p = 0.02). In per protocol analysis (n = 141), 14 (18%) primary events occurred in the control group vs. 4 (6%) in the LAACS group (hazard ratio 0.3; 95% CI: 0.1-1.0, p = 0.05). CONCLUSIONS: In a real-world setting, LAACS in addition to elective open-heart surgery was associated with lower risk of post-operative ischemic brain injury. The protective effect was not conditional on AF/OAC status at baseline. TRIAL REGISTRATION: LAACS study, clinicaltrials.gov NCT02378116 , March 4th 2015, retrospectively registered.

Deep sequencing of atrial fibrillation patients with mitral valve regurgitation shows no evidence of mosaicism but reveals novel rare germline variants.

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia. Valvular heart disease is a strong predictor, yet the underlying molecular mechanisms are unknown. OBJECTIVE: The purpose of this study was to investigate the prevalence of somatic variants in AF candidate genes in an AF patient population undergoing surgery for mitral valve regurgitation (MVR) to determine whether these patients are genetically predisposed to AF. METHODS: DNA was extracted from blood and left atrial tissue from 44 AF patients with MVR. Using next-generation sequencing, we investigated 110 genes using the HaloPlex Target Enrichment System. MuTect software was used for identification of somatic point variants. We functionally characterized selected variants using electrophysiologic techniques. RESULTS: No somatic variants were identified in the cardiac tissue. Thirty-three patients (75%) had a rare germline variation in ≥1 candidate genes. Fourteen variants were novel. Fifteen variants were predicted damaging or likely damaging in ≥6 in silico predictions. We identified rare variants in genes never directly associated with AF: KCNE4, SCN4B, NEURL1, and CAND2. Interestingly, 7 patients (16%) had variants in genes involved in cellular potassium handling. The variants KCNQ1 (p.G272S) and KCNH2 (p.A913V) resulted in gain of function due to faster activation (KCNQ1) and slowed deactivation kinetics (KCNQ1, KCNH2). CONCLUSION: We did not find any somatic variants in patients with AF and MVR. Surprisingly, we found that our cohort of non-lone AF patients might, like lone AF patients, be predisposed to AF by rare germline variants. Our findings emphasize the extent of still unknown factors in the pathogenesis of AF.

Transcatheter mitral valve implantation via transapical approach: an early experience.

OBJECTIVES: As many as 50% of patients with severe symptomatic mitral valve regurgitation are denied surgical valve replacement or repair due to high operative risk. We describe an early series of cases of transcatheter implantation with a CardiAQ™ mitral valve via a transapical approach. METHODS: Three consecutive patients with an Society of Thoracic Surgeons (STS) mortality score of >22% were selected for transcatheter mitral valve implantation (TMVI) on compassionate grounds. All patients were elderly, had severe mitral regurgitation (MR), were in Class IV heart failure and deemed unsuitable for the MitraClip. Two of the patients had functional MR in the setting of ischaemic cardiomyopathy with left ventricular ejection fraction (LVEF) <40%, deemed while the remaining patient had chordal rupture with extensive anterior leaflet flail (preserved LVEF). Comorbidities included previous coronary artery bypass surgery (n = 2), severe pulmonary hypertension (n = 1) and moderate to severe chronic renal failure (n = 3). A CardiAQ mitral valve was implanted using fluoroscopy and transoesophageal (TEE) guidance via a standard transapical approach. RESULTS: Accurate prosthesis positioning and deployment with immediate elimination of the MR was achieved in all 3 cases. Two patients made full clinical recovery and were discharged home. Post-procedural TEE performed on Days 1, 30 and 60 days showed good valve function, stable valve position and minimal LVOT gradient. One patient expired on the postoperative day 9 due to pneumonia. CONCLUSIONS: TMVI using the CardiAQ™ device via a transapical approach is feasible and effective.

Graft patency after off-pump coronary artery bypass surgery is inferior even with identical heparinization protocols: results from the Danish On-pump Versus Off-pump Randomization Study (DOORS).

OBJECTIVE: To determine whether graft patency after on-pump and off-pump coronary artery bypass surgery is similar when performed using the same heparinization protocol. METHODS: In a randomized, controlled, multicenter trial, 900 patients more than 70 years of age received either on-pump or off-pump coronary artery bypass surgery. Heparin was given to achieve an activated clotting time of 400 seconds before arteriotomy in both groups. After the procedure, protamine sulfate was given to revert the activated clotting time to less than 120 seconds. Coronary angiography was performed 6 months after the operation and graft patency was assessed by independent blinded observers. RESULTS: A total of 481 patients underwent angiography. In the off-pump group, 561 (79%) of 710 grafts were open, 65 (9%) were stenotic, and 84 (12%) were occluded. In the on-pump group, 549 (86%) of 650 grafts were open, 38 (5%) were stenotic, and 63 (9%) were occluded. The difference between the proportion of open grafts was statistically significant in favor of on-pump surgery (P=.01). The proportion of open left internal thoracic artery grafts was 95% in both groups. Perioperative use of intracoronary shunts did not increase the risk of stenosis of the coronary artery distal to the anastomosis. CONCLUSIONS: Despite comparable heparinization, graft patency after off-pump surgery was inferior to that after on-pump surgery.

OPCAB surgery is cost-effective for elderly patients.

OBJECTIVE: To determine the cost-effective operative strategy for coronary artery bypass surgery in patients above 70 years. DESIGN: Randomized, controlled trial of 900 patients above 70 years of age subjected to coronary artery bypass surgery. Patients were randomized to either on-pump or off-pump coronary artery bypass surgery. Data on direct and indirect costs were prospectively collected. Preoperatively and six months postoperatively, quality of life was assessed using EuroQol-5D questionnaires. Perioperative in-hospital costs and costs of re-intervention were included. RESULTS: The Summary Score of EuroQol-5D increased in both groups between preoperatively and postoperatively. In the on-pump group, it increased from 0.75 (0.16) (mean (SD)) to 0.84 (0.17), while the increase in the off-pump group was from 0.75 (0.15) to 0.84 (0.18). The difference between the groups was 0.0016 QALY and not significantly different. The mean costs were 148.940 D.Kr (CI, 130.623 D.Kr-167.252 D.Kr) for an on-pump patient and 138.693 D.Kr (CI, 123.167 D.Kr-154.220 D.Kr) for an off-pump patient. The ICER base-case point estimate was 6,829,999 D.Kr/QALY. The cost-effectiveness acceptability curve showed 89% probability of off-pump being cost-effective at a threshold value of 269,400 D.Kr/QALY. CONCLUSIONS: Off-pump surgery tends to be more cost-effective than on-pump surgery. Long-term comparisons are warranted.

On-pump versus off-pump coronary artery bypass surgery in elderly patients: results from the Danish on-pump versus off-pump randomization study.

BACKGROUND: Conventional coronary artery bypass grafting performed with the use of cardiopulmonary bypass is a well-validated treatment for patients with ischemic heart disease. Off-pump coronary artery bypass grafting (OPCAB) has been suggested to reduce the number of perioperative complications, especially in elderly patients. METHODS AND RESULTS: In a multicenter, randomized trial, we assigned 900 patients >70 years of age to conventional coronary artery bypass grafting or OPCAB surgery. After 30 days, a blinded end-point committee assessed whether a combined end point of death, stroke, or myocardial infarction had occurred. At baseline and 6 months postoperatively, self-assessed quality of life was measured with the Medical Outcomes Study Short Form-36 and EuroQol-5D questionnaires. A 6-month follow-up of mortality was performed through the Danish National Registry. The proportion of patients experiencing the combined end point within 30 days was 10.2% for conventional coronary artery bypass grafting and 10.7% for OPCAB. Implied risk difference of 0.4% (with a 95% confidence interval, -3.6 to 4.4) showed nonsignificance in a standard test for equality (P=0.83) and for noninferiority with an inferiority margin of 0.5% (P=0.49). At the 6-month follow-up, mortality was 4.7% compared with 4.2% (P=0.75). Both groups showed significant improvement in self-assessed health-related quality of life. CONCLUSIONS: Both conventional coronary artery bypass grafting and OPCAB are safe procedures that improved the quality of life when performed in elderly patients. No major differences in intermediate-term outcomes were found. However, the noninferiority of OPCAB with the prespecified margin could not be confirmed.

The impact of avoiding cardiopulmonary by-pass during coronary artery bypass surgery in elderly patients: the Danish On-pump Off-pump Randomisation Study (DOORS).

BACKGROUND: Coronary Artery Bypass Graft operation for ischemic heart disease provides improved quality of life and, in some patients, prolonged survival. Concern has, however, been raised about complications that may be related to the use of cardiopulmonary by-pass (CPB) and aortic cross-clamping. It has been hypothesized that when coronary artery by-pass grafting is performed without the use of CPB, the rate of serious complications is reduced. METHODS/DESIGN: The trial is designed as an open, randomized, controlled, clinical trial with blinded assessment of end-points. Patients at or above 70 years of age, referred for surgical myocardial revascularisation, are included and randomised to receive coronary artery by-pass grafting either with or without the use of CPB and aortic cross-clamping. Follow-up is performed by clinical, biochemical, electrocardiographic, and angiographic data that are evaluated by independent committees that are blinded with respect to the result of the randomisation. End points include mortality, stroke, myocardial infarction, graft patency, quality of life, and cost-effectiveness. The trial is performed in four different Danish, cardiac surgery centres. TRIAL REGISTRATION: ClinicalTrials.gov NCT00123981.