Sleep apnea in patients undergoing coronary artery bypass grafting: Impact on perioperative outcomes

Sleep-disordered breathing is common in patients with coronary artery disease undergoing coronary artery bypass grafting. Sleep-disordered breathing is associated with increased perioperative morbidity, arrhythmias (e.g. atrial fibrillation) and mortality. This study investigated the impact of sleep-disordered breathing on the postoperative course after coronary artery bypass grafting, including development of atrial fibrillation. This prospective single-centre cohort study included adults undergoing coronary artery bypass grafting. All were screened for sleep-disordered breathing (polygraphy) and atrial fibrillation (electrocardiogram) preoperatively; those with known sleep-disordered breathing or atrial fibrillation were excluded. Endpoints included new-onset atrial fibrillation, duration of mechanical ventilation, time in the intensive care unit, and postoperative infection. Regression analysis was performed to identify associations between sleep-disordered breathing and these outcomes. A total of 508 participants were included (80% male, median age 68 years). The prevalence of any (apnea-hypopnea index ≥ 5 per hr), moderate (apnea-hypopnea index = 15-30 per hr) and severe (apnea-hypopnea index > 30 per hr) sleep-disordered breathing was 52.9%, 9.3% and 10.2%, respectively. All-cause 30-day mortality was 0.98%. After adjustment for age and sex, severe sleep-disordered breathing was associated with longer respiratory ventilation support (crude odds ratio [95% confidence interval] 5.28 [2.18-12.77]; p < 0.001) and higher postoperative infection rates (crude odds ratio 3.32 [1.45-7.58]; p < 0.005), but not new-onset atrial fibrillation or mortality. New-onset atrial fibrillation was significantly associated with postoperative infection and prolonged hospital stay. The significant associations between sleep-disordered breathing and several adverse outcomes after coronary artery bypass grafting support the need for preoperative sleep-disordered breathing screening in individuals undergoing cardiac surgery.

Echocardiographic mechanical dyssynchrony predicts long-term mortality in patients with cardiac resynchronisation therapy

Cardiac resynchronisation therapy (CRT) is an established treatment for patients with symptomatic heart failure with reduced left ventricular ejection fraction (LVEF ≤ 35%; HFrEF) and conduction disturbances (QRS duration ≥ 130 ms). The presence of mechanical dyssynchrony (MD) on echocardiography has been hypothesised to be of predictive value in determining indication for CRT. This study investigated the impact of MD (apical rocking [AR] and septal flash [SF]) on long-term survival in CRT recipients. HFrEF patients (n = 425; mean age 63.0 ± 10.6 years, 72.3% male, 60.7% non-ischaemic aetiology) with a guideline-derived indication for CRT underwent device implantation. MD markers were determined at baseline and after a mean follow-up of 11.5 ± 8.0 months; long-term survival was also determined. AR and/or SF were present in 307 (72.2%) participants at baseline. During post-CRT follow-up, AR and/or SF disappeared in 256 (83.4%) patients. Overall mean survival was 95.9 ± 52.9 months, longer in women than in men (109.1 ± 52.4 vs. 90.9 ± 52.4 months; p < 0.001) and in younger (< 60 years) versus older patients (110.6 ± 53.7 vs. 88.6 ± 51.1 months; p < 0.001). Patients with versus without MD markers at baseline generally survived for longer (106.2 ± 52.0 vs. 68.9 ± 45.4 months; p < 0.001), and survival was best in patients with resolved versus persisting MD (111.6 ± 51.2 vs. 79.7 ± 47.6 months p < 0.001). Age and MD at baseline were strong predictors of long-term survival in HFrEF patients undergoing CRT on multivariate analysis. Novel echocardiography MD parameters in HFrEF CRT recipients predicted long-term mediated better outcome, and survival improved further when AR and/or SF disappear after CRT implantation.

Predicting procedural success in patients treated with Cardioband system for severe tricuspid regurgitation by employing a random forest algorithm

Background

Severe tricuspid regurgitation (TR) is associated with high morbidity and mortality despite optimal medical treatment. Transcatheter tricuspid valve intervention (TTVI) is therefore emerging as a novel treatment option, fueling the hope to prolong survival and reduce rehospitalization for heart failure. Obviously, procedural success of TTVI is an important determinant of survival, but predictors for procedural success in patients treated with Cardioband system, which mimics the surgical approach by implanting an annular reduction system and hence targets tricuspid annulus dilatation as the central pathology in most patients, are largely elusive.

Purpose

This study aims to refine prediction of procedural success in patients with severe TR undergoing TTVI with Cardioband system by employing a random forest algorithm.

Methods

Procedural success was evaluated in 72 patients enrolled at two tertiary centers in Germany between 2018 and 2020. Key inclusion criterion was TR ≥ III/V° with high symptomatic burden despite optimal medical treatment. Procedural success war defined as patient alive at the end of the procedure, successful Cardioband implantation, and TR reduction ≥ II/V° as assessed on transthoracic echocardiography before discharge. Since 66.7% of patients were classified as “success”, a synthetic minority over-sampling technique was applied in order to train the random forest algorithm on a balanced data set.

Results

A random forest algorithm reached 85.4% accuracy (AUC: 0.923) in predicting procedural success in a balanced data set using eight parameters from pre-procedural echocardiography as input variables. Partial dependence analysis revealed that enlargement of the tricuspid valve (TV) anteroseptal diameter was most important for model accuracy. Applied to the real-world data set (24 patients classified as “failure” and 48 patients classified as “success”), the now trained random forest algorithm predicted procedural success with high sensitivity (70.8%) and specificity (100.0%), significantly outperforming the no information rate (p-value: 0.0069). Patients with low probability for success were characterized by impaired right ventricular function (TAPSE: 15.5±3.63 mm) and enlarged right sided cardiac diameters (basal right ventricular diameter: 51.6±3.79 mm; TV anteroseptal diameter: 45.0±5.10 mm). Notably, systolic pulmonary artery pressure (sPAP) and TV effective regurgitant orifice area were negatively correlated (R: −0.3004, p-value: 0.0322), and elevation in sPAP was attenuated in patients with low probability for procedural success (sPAP: 34.0±11.7 mmHg).

Conclusion

A random forest algorithm enables precise prediction of procedural success in patients treated with Cardioband system. TR reduction ≥ II/V° appears less achievable in patients with advanced stages of right heart failure, emphasizing the importance of adequate patient selection and timing of intervention.

Funding Acknowledgement

Type of funding sources: None.