Outlier identification and monitoring of institutional or clinician performance: an overview of statistical methods and application to national audit data

BACKGROUND

Institutions or clinicians (units) are often compared according to a performance indicator such as in-hospital mortality. Several approaches have been proposed for the detection of outlying units, whose performance deviates from the overall performance.

METHODS

We provide an overview of three approaches commonly used to monitor institutional performances for outlier detection. These are the common-mean model, the 'Normal-Poisson' random effects model and the 'Logistic' random effects model. For the latter we also propose a visualisation technique. The common-mean model assumes that the underlying true performance of all units is equal and that any observed variation between units is due to chance. Even after applying case-mix adjustment, this assumption is often violated due to overdispersion and a post-hoc correction may need to be applied. The random effects models relax this assumption and explicitly allow the true performance to differ between units, thus offering a more flexible approach. We discuss the strengths and weaknesses of each approach and illustrate their application using audit data from England and Wales on Adult Cardiac Surgery (ACS) and Percutaneous Coronary Intervention (PCI).

RESULTS

In general, the overdispersion-corrected common-mean model and the random effects approaches produced similar p-values for the detection of outliers. For the ACS dataset (41 hospitals) three outliers were identified in total but only one was identified by all methods above. For the PCI dataset (88 hospitals), seven outliers were identified in total but only two were identified by all methods. The common-mean model uncorrected for overdispersion produced several more outliers. The reason for observing similar p-values for all three approaches could be attributed to the fact that the between-hospital variance was relatively small in both datasets, resulting only in a mild violation of the common-mean assumption; in this situation, the overdispersion correction worked well.

CONCLUSION

If the common-mean assumption is likely to hold, all three methods are appropriate to use for outlier detection and their results should be similar. Random effect methods may be the preferred approach when the common-mean assumption is likely to be violated.

Feasibility of transcaval access TAVI in morbidly obese patients: A single-center experience

OBJECTIVES

We report a single-center experience in utilizing the transcaval-access transcatheter aortic valve implantation (TAVI) as an alternative approach in morbidly obese patients.

BACKGROUND

Morbidly obese patients present frequently for TAVI. Transfemoral arterial access TAVI in these patients is technically challenging due to deep arterial access, resulting in a higher risk of vascular complications. Transcaval access TAVI is increasingly used in patients with prohibitive iliofemoral arterial access.

METHODS

We used the transcaval approach for eight morbidly obese patients who had otherwise technically feasible femoral arterial access. This technique provides an alternative arterial access point that potentially circumvents some of the challenges relating to femoral arterial access.

RESULTS

We report eight morbidly obese patients with a mean body mass index of 42.3 ± 6.2 kg/m² who underwent transcaval access TAVI at our center (mean EuroScore II 2.47 ± 1.83%). The patient mean age was 70.3 ± 9.8 years; six were female. All eight patients underwent a successful and uncomplicated procedure. The median time to discharge was 2 days and all patients were alive at 30 days.

CONCLUSIONS

Transcaval access TAVI is a feasible alternative for morbidly obese patients and may reduce vascular complications. Further data are required to evaluate the safety of this approach.

Effect of Transcatheter Aortic Valve Implantation vs Surgical Aortic Valve Replacement on All-Cause Mortality in Patients With Aortic Stenosis: A Randomized Clinical Trial

IMPORTANCE

Transcatheter aortic valve implantation (TAVI) is a less invasive alternative to surgical aortic valve replacement and is the treatment of choice for patients at high operative risk. The role of TAVI in patients at lower risk is unclear.

OBJECTIVE

To determine whether TAVI is noninferior to surgery in patients at moderately increased operative risk.

DESIGN, SETTING, AND PARTICIPANTS

In this randomized clinical trial conducted at 34 UK centers, 913 patients aged 70 years or older with severe, symptomatic aortic stenosis and moderately increased operative risk due to age or comorbidity were enrolled between April 2014 and April 2018 and followed up through April 2019.

INTERVENTIONS

TAVI using any valve with a CE mark (indicating conformity of the valve with all legal and safety requirements for sale throughout the European Economic Area) and any access route (n = 458) or surgical aortic valve replacement (surgery; n = 455).

MAIN OUTCOMES AND MEASURES

The primary outcome was all-cause mortality at 1 year. The primary hypothesis was that TAVI was noninferior to surgery, with a noninferiority margin of 5% for the upper limit of the 1-sided 97.5% CI for the absolute between-group difference in mortality. There were 36 secondary outcomes (30 reported herein), including duration of hospital stay, major bleeding events, vascular complications, conduction disturbance requiring pacemaker implantation, and aortic regurgitation.

RESULTS

Among 913 patients randomized (median age, 81 years [IQR, 78 to 84 years]; 424 [46%] were female; median Society of Thoracic Surgeons mortality risk score, 2.6% [IQR, 2.0% to 3.4%]), 912 (99.9%) completed follow-up and were included in the noninferiority analysis. At 1 year, there were 21 deaths (4.6%) in the TAVI group and 30 deaths (6.6%) in the surgery group, with an adjusted absolute risk difference of -2.0% (1-sided 97.5% CI, -∞ to 1.2%; P < .001 for noninferiority). Of 30 prespecified secondary outcomes reported herein, 24 showed no significant difference at 1 year. TAVI was associated with significantly shorter postprocedural hospitalization (median of 3 days [IQR, 2 to 5 days] vs 8 days [IQR, 6 to 13 days] in the surgery group). At 1 year, there were significantly fewer major bleeding events after TAVI compared with surgery (7.2% vs 20.2%, respectively; adjusted hazard ratio [HR], 0.33 [95% CI, 0.24 to 0.45]) but significantly more vascular complications (10.3% vs 2.4%; adjusted HR, 4.42 [95% CI, 2.54 to 7.71]), conduction disturbances requiring pacemaker implantation (14.2% vs 7.3%; adjusted HR, 2.05 [95% CI, 1.43 to 2.94]), and mild (38.3% vs 11.7%) or moderate (2.3% vs 0.6%) aortic regurgitation (adjusted odds ratio for mild, moderate, or severe [no instance of severe reported] aortic regurgitation combined vs none, 4.89 [95% CI, 3.08 to 7.75]).

CONCLUSIONS AND RELEVANCE

Among patients aged 70 years or older with severe, symptomatic aortic stenosis and moderately increased operative risk, TAVI was noninferior to surgery with respect to all-cause mortality at 1 year.

TRIAL REGISTRATION

isrctn.com Identifier: ISRCTN57819173.

Apical versus subclavian transcatheter aortic valve implantation: An 8-year United Kingdom analysis

OBJECTIVES

Subclavian (SC) and transapical (TA) approaches are the main alternatives to the default femoral delivery for transcatheter aortic valve implantation (TAVI). The aim of this study was to compare complications and morbidity/mortality associated with SC and TA in a long-term time frame.

METHODS

From January 2007 to July 2015, 1506 patients underwent TAVI surgery in 36 United Kingdom TAVI centers. Primary outcomes were complications according to VARC-2 criteria. The secondary outcome was long-term survival.

RESULTS

The enrolled patients were distributed as follows: 1216 in the TA group and 290 in the SC group. There were no differences in the rates of acute myocardial infarction, emergency valve-in-valve, paravalvular leak, balloon post dilatation, cardiac tamponade, stroke, renal replacement therapy, vascular injuries, and 30-day mortality among the groups. Conversely, the rate of permanent pacemaker implantation (p = .02), the procedural time duration (p = .04), and the 12-month mortality (p = .03) was higher in SC than in TA, while in-hospital length of stay was reduced in SC than in TA (p = .01). Up to 8 years, the long-term mortality was not different among groups (p = .77), and no difference in long-term survival between self- versus balloon-expandable devices was found (p = .26).

CONCLUSIONS

According to our results, TA provided the best 12-month survival compared to SC, while the long-term survival up to 2900 days is not significantly different between groups, so SC and TA may both represent a safe non-femoral access if femoral is precluded.

Geographical variations in left main coronary artery revascularisation: a prespecified analysis of the EXCEL trial

BACKGROUND

The EXCEL trial reported similar five-year rates of the primary composite outcome of death, myocardial infarction (MI), or stroke after percutaneous coronary intervention (PCI) compared with coronary artery bypass grafting (CABG) for treatment of obstructive left main coronary artery disease (LMCAD).

AIMS

We sought to determine whether these outcomes remained consistent regardless of geography of enrolment.

METHODS

We performed a prespecified subgroup analysis based on regional enrolment.

RESULTS

Among 1,905 patients randomised to PCI (n=948) or CABG (n=957), 1,075 (56.4%) were recruited at 52 European Union (EU) centres, and 752 (39.5%) were recruited at 67 North American (NA) centres. EU versus NA patients varied according to numerous baseline demographics, anatomy, pharmacotherapy and procedural characteristics. Nonetheless, the relative rates of the primary endpoint after PCI versus CABG were consistent across EU versus NA centres at 30 days and 5 years. However, NA participants had substantially higher late rates of ischaemia-driven revascularisation (IDR) after PCI, driven predominantly by the need for greater target vessel and lesion revascularisation. This culminated in a significant difference in the relative risk of the secondary composite outcome of death, MI, stroke, or IDR at 5 years (p_interaction=0.02).

CONCLUSIONS

In the EXCEL trial, the relative risks for the 30-day and five-year primary composite outcome of death, MI or stroke after PCI versus CABG were consistent irrespective of geography. However, five-year rates of IDR after PCI were significantly higher in NA centres, a finding the Heart Team and patients should consider when making treatment decisions. ClinicalTrials.gov identifier: NCT01205776.

Surgical aortic valve replacement in the era of transcatheter aortic valve implantation: a review of the UK national database

OBJECTIVES

To date the reported outcomes of surgical aortic valve replacement (SAVR) are mainly in the settings of trials comparing it with evolving transcatheter aortic valve implantation. We set out to examine characteristics and outcomes in people who underwent SAVR reflecting a national cohort and therefore 'real-world' practice.

DESIGN

Retrospective analysis of prospectively collected data of consecutive people who underwent SAVR with or without coronary artery bypass graft (CABG) surgery between April 2013 and March 2018 in the UK. This included elective, urgent and emergency operations. Participants' demographics, preoperative risk factors, operative data, in-hospital mortality, postoperative complications and effect of the addition of CABG to SAVR were analysed.

SETTING

27 (90%) tertiary cardiac surgical centres in the UK submitted their data for analysis.

PARTICIPANTS

31 277 people with AVR were identified. 19 670 (62.9%) had only SAVR and 11 607 (37.1%) had AVR+CABG.

RESULTS

In-hospital mortality for isolated SAVR was 1.9% (95% CI 1.6% to 2.1%) and was 2.4% for AVR+CABG. Mortality by age category for SAVR only were: <60 years=2.0%, 60-75 years=1.5%, >75 years=2.2%. For SAVR+CABG these were; 2.2%, 1.8% and 3.1%. For different categories of EuroSCORE, mortality for SAVR in low risk people was 1.3%, in intermediate risk 1% and for high risk 3.9%. 74.3% of the operations were elective, 24% urgent and 1.7% emergency/salvage. The incidences of resternotomy for bleeding and stroke were 3.9% and 1.1%, respectively. Multivariable analyses provided no evidence that concomitant CABG influenced outcome. However, urgency of the operation, poor ventricular function, higher EuroSCORE and longer cross clamp and cardiopulmonary bypass times adversely affected outcomes.

CONCLUSIONS

Surgical SAVR±CABG has low mortality risk and a low level of complications in the UK in people of all ages and risk factors. These results should inform consideration of treatment options in people with aortic valve disease.

Mobility aids predict mortality after transcatheter aortic valve implantation

BACKGROUND

Selection of appropriate patients for transcatheter aortic valve implantation (TAVI) can be challenging. Many factors can influence post-procedure outcomes. Traditional surgical scoring systems do not discriminate effectively. Medical parameters and functional indices can characterize mortality risk. Mobility is an important predictive functional index but is largely defined using subjective criteria.

AIM

To describe the relationship between mobility, objectively defined by the requirement for gait aids to ambulate, and all-cause 30-day and long-term mortality in patients undergoing TAVI.

METHODS

Mobility aid use was assessed in 1444 consecutive patients undergoing TAVI in a single center. Patients were categorized into "unaided," "1-stick," and "higher aid" groups based on the Brighton Mobility Index. Mortality tracking was obtained via the NHS Spine Portal in February 2021.

RESULTS

Patients were aged 82 (IQR 78-86). 66% of patients walked unaided, 26% walked with 1 stick, and 8% required more assistance (e.g., 2 sticks, a Rollator, a Zimmer frame, or a wheelchair). Overall 30-day mortality for the whole cohort was 3.5%; 1-year mortality was 12.2%. Mobility was a significant predictor of 30-day mortality (p = 0.025). Use of a higher aid was associated with a mortality odds ratio of 2.83 (95% CI: 1.39-5.74). Mobility was also a significant predictor of long-term mortality (p < 0.001). Odds ratios for 1-stick and higher aid groups were 1.45 (95% CI: 1.21-1.72) and 2.01 (95% CI: 1.55-2.60), respectively.

CONCLUSION

Objective assessment of mobility by gait aid use predicts both short and long-term survival in patients undergoing TAVI. Increased dependence on mobility aids is associated with a worse prognosis.

1638 Decade-Long Trends in Surgery for Acute Type A Aortic Dissection

Background

Little is known about unwarranted variations in care and outcomes of patients who undergo surgical repair for type A acute aortic dissection(TAAD). We aim to investigate decade-long trends in TAAD surgical repair in England.

Method

Retrospective review of the National Institute for Cardiovascular Outcomes Research (NICOR) National Adult Cardiac Surgery Audit (NACSA) registry from January 2009 to December 2018 , which prospectively collects demographic and peri-operative clinical information for all adult cardiac surgery procedures in the UK.

Results

Over the 10-year period,3,686 TAAD patients underwent surgical repair in England. A steady doubling in the overall number of operations conducted in England was observed from 237 cases recorded in 2009 to 510 in 2018. Number of procedures per hospital per year also doubled, from 10 in 2009 to 21 in 2018. The risk profile of the operated patients remained unchanged. Overall, in-hospital mortality was 17.4% with a trend toward lower mortality in the most recent years (from 22.8% in 2009 to 14.7% in 2018). There was a significant variation in operative mortality across regions with a trend towards lower mortality in regions with a high-volume hospital.

Conclusions

Surgery is the only treatment for acute TAAD but is associated with high mortality. Prompt diagnosis and referral to a specialist center is paramount. The number of operations conducted in England has doubled in 10 years and the associated survival following surgery has improved. Regional variations exist in service provision with a trend towards better survival in high volume centers.

Decade-long trends in surgery for acute Type A aortic dissection in England: A retrospective cohort study

Background

Little is known about variations in care and outcomes of patients undergoing surgical repair for type A aortic dissection(TAAD). We aim to investigate decade-long trends in TAAD surgical repair in England.

Methods

Retrospective review of the National Adult Cardiac Surgery Audit, which prospectively collects demographic and peri‑operative information for all major adult cardiac surgery procedures performed in the UK. We identified patients undergoing surgery for TAAD from January 2009-December 2018, reviewed trends in operative frequency, patient demographics, and mortality.

Findings

Over the 10-year period,3,680 TAAD patients underwent surgical repair in England. A doubling in the overall number of operations conducted in England was observed (235 cases in 2009 to 510 in 2018). Number of procedures per hospital per year also doubled(9 in 2009 to 23 in 2018). Overall, in-hospital mortality was 17.4% with a trend toward lower mortality in recent years(23% in 2009 to 14.7% in 2018). There was a significant variation in operative mortality between hospitals and surgeons. We also found that most patients presented towards the middle of the week and during winter.

Interpretation

Surgery is the only treatment for acute TAAD but is associated with high mortality. Prompt diagnosis and referral to a specialist center is paramount. The number of operations conducted in England has doubled in 10 years and the associated survival has improved. Variations exist in service provision with a trend towards better survival in high volume centers.

Funding

British Heart Foundation and NIHR Biomedical Research center(University Hospitals Bristol and Weston NHS Foundation Trust and University of Bristol).

Trends and outcomes for cardiac surgery in the United Kingdom from 2002 to 2016

Objectives

Cardiac surgery has evolved significantly since the turn of the century. The objective of this study was to investigate trends in cardiac surgery activity and outcomes in the United Kingdom utilizing a mandatory national cardiac surgical clinical database in the context of a comprehensive public health care system (ie, the UK National Health Service).

Methods

Data for all cardiac surgery procedures performed between 2002 and 2016 were extracted from the UK National Adult Cardiac Surgery Audit database. Data are validated and cleaned using reproducible algorithms. Trends in activity and outcomes were analyzed by fiscal year using linear regression.

Results

A total of 534,067 procedures were performed during the study period with the number of cases per year peaking in 2008/2009 at 41,426. Despite an increase in patient age and mean logistic European System for Cardiac Operative Risk Evaluation score, the in-hospital mortality rate for all cardiac surgery has fallen from 4.0% to 2.8% (P < .001). The number of isolated coronary artery bypass graft procedures has steadily declined but the total number of valve procedures has steadily increased (both P values < .001). The number of thoracic aortic procedures performed each year has doubled (P < .001), but the incidence of redo procedures has steadily declined. The proportion of emergency and salvage procedures has remained stable.

Conclusions

This study, which covers all cardiac surgery procedures performed in the United Kingdom for fiscal years between 2002 and 2016, demonstrates that despite an increase in patient risk profile, there has been a consistent reduction in in-hospital mortality. A number of other markers associated with quality have also improved.

Coronary artery bypass surgery in the UK, trends in activity and outcomes from a 15-year complete national series

OBJECTIVES

The aim of this study was to review the UK national trends in activity and outcome in coronary artery bypass graft (CABG) over a 15-year period (2002-2016).

METHODS

Validated data collected (2002-2016) and uploaded to National Institute for Cardiovascular Outcomes Research were used to generate summary data from the National Adult Cardiac Surgery Audit Database for the analysis. Logistic European System of Cardiac Operative Risk Evaluation was used for risk stratification with recalibration applied for governance. Data were analysed by financial year and presented as numerical, categorical, %, mean and standard deviation where appropriate. Mortality was recorded as death in hospital at any time after index CABG operation.

RESULTS

A total of 347 626 CABG procedures (282 883 isolated CABG, 61 109 CABG and valve and 4132 redo CABG) were recorded. Over this period annual activity reduced from 66.6% of workload to 41.7%. The mean age for isolated CABG was 65.7 years. The mean log European System of Cardiac Operative Risk Evaluation was 3.1, 5.9 and 23.2 for elective, urgent and emergency isolated CABG, respectively. There was a decline in the observed mortality for all procedures. Overall mortality for isolated CABG surgery is now 1.0% and only 0.6% for elective operations.

CONCLUSIONS

Quality of care and risk-adjusted mortality rates have consistently improved over the last 15 years despite the increasing risk profile of patients. There have been a consistent decline in overall case volumes and a three-fold increase in elderly cases.

Balloon seal separation leading to SAPIEN 3 transcatheter heart valve deployment failure: Complications and management

We present two cases of failure of balloon inflation secondary to balloon separation from the delivery catheter when implanting the SAPIEN 3 transcatheter heart valve (Edwards Lifesciences, Irvine, CA, USA). Although very uncommon, this is a potentially disastrous complication of transcatheter intervention. Case 1 highlights the complexity of the problem when it occurs and subsequent complications. Case 2 highlights how to manage this issue successfully.

Elective versus urgent in-hospital transcatheter aortic valve implantation

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is maturing as a treatment option and is now often undertaken during an unscheduled index hospital admission. The aim of this study was to look at procedural and mid-term outcomes of patients undergoing elective versus urgent in-hospital transcatheter aortic valve implantation.

METHODS

We identified a total of 1,157 patients who underwent TAVI between November 2007 and November 2019 at the Sussex Cardiac Centre in the UK. We compared the demographics, procedural outcomes, 30-day and 1-year mortality between elective and urgent patients. Emergency and salvage TAVI cases were excluded.

RESULTS

Of the 1,157 patients who underwent the procedure, 975 (84.3%) had elective while 182 (15.7%) had urgent TAVI. Predominant aortic stenosis was more frequent in elective patients (91.7% vs. 77.4%); p < .01), while predominant aortic regurgitation was seen more commonly in the urgent group (11.5% vs. 4.2%; p < .01). Implantation success was similar between the elective (99.1%) and urgent group (99.4%). In-hospital (1.65% vs. 1.3%: p .11), 30 day (3.5% vs. 3.3%: p .81) and 1 year (10.9% vs. 11%; p .81) mortality rates were similar in the elective and urgent groups, respectively.

CONCLUSIONS

In contemporary practice, urgent TAVI undertaken on the index admission can be performed at similar risk to elective outpatient TAVI.

Aortic valve surgery in the UK, trends in activity and outcomes from a 15-year complete national series

OBJECTIVES

Since the turn of the century, cardiac surgery has evolved quite notably. This study sought to investigate the trends in aortic valve surgery activity and subsequent outcomes in the UK by using a mandatory national cardiac surgical clinical database within the context of a comprehensive public healthcare system (National Health Service).

METHODS

The UK National Adult Cardiac Surgery Audit database provided data for aortic valve surgery procedures performed between 2002 and 2016, and the data were validated and cleaned using reproducible algorithms. The findings and trends in in activity and outcomes were then analysed by financial year.

RESULTS

During the study period, a total of 148 862 procedures were performed, with the number of cases per year peaking in 2014/2015 at 12 483. The mean in-hospital mortality rate for all aortic valve surgery has fallen from 5.6% to 3.4%, despite an increase in patient age and mean logistic EuroSCORE. While the number of isolated aortic valve replacements has remained stable at around 5000 per year, aortic valve replacement and coronary artery bypass graft have increased to over 3200 with transcatheter aortic valve implantation activity continuing to increase.

CONCLUSIONS

This study demonstrates that despite an increase in patient risk profile, there has been a consistent reduction in in-hospital mortality within all aortic valve surgery procedures performed in the UK over a 15-year period. Increasing catheter-based interventions have not yet resulted in a significant decrease in surgical aortic valve replacements in the UK.

Neuroprotective strategies in acute aortic dissection: an analysis of the UK National Adult Cardiac Surgical Audit

OBJECTIVES

The risk of brain injury following surgery for type A aortic dissection (TAAD) remains substantial and no consensus has still been reached on which neuroprotective technique should be preferred. We aimed to investigate the association between neuroprotective strategies and clinical outcomes following TAAD repair.

METHODS

Using the UK National Adult Cardiac Surgical Audit, we identified 1929 patients undergoing surgery for TAAD (2011-2018). Deep hypothermic circulatory arrest (DHCA) only, unilateral (uACP), bilateral antegrade cerebral perfusion (bACP) and retrograde cerebral perfusion were used in 830, 117, 760 and 222 patients, respectively. The primary end point was a composite of death and/or cerebrovascular accident (CVA). Generalized linear mixed model was used to adjust the effect of neuroprotective strategies for other confounders.

RESULTS

The use of bACP was associated with longer circulatory arrest (CA) compared to other strategies. There was a trend towards lower incidence of death and/or CVA using uACP only for shorter CA. In particular, primary end point rate was 27.7% overall and 26.5%, 12.5%, 28.0% and 22.9% for CA <30 min and 28.6%, 30.4%, 33.3% and 33.0% for CA ≥30 min with DHCA only, uACP, bACP and retrograde cerebral perfusion, respectively. The use of DHCA only was associated with five-fold [odds ratio (OR) 5.35, 95% confidence interval (CI) 1.36-21.02] and two-fold (OR 1.77, 95% CI 1.01-3.09) increased risk of death and/or CVA compared to uACP and bACP, respectively, but the effect of uACP was significantly associated with CA duration (hazard ratio 0.97, 95% CI 0.94-0.99; P = 0.04).

CONCLUSIONS

In TAAD repair, the use of uACP and bACP was associated with a lower adjusted risk of death and/or CVA when compared to DHCA. uACP can offer some advantage but only for a shorter CA duration.

Survival relative to pacemaker status after transcatheter aortic valve implantation

OBJECTIVES

To determine whether a permanent pacemaker (PPM) in situ can enhance survival after transcatheter aortic valve implantation (TAVI), in a predominantly inoperable or high risk cohort.

BACKGROUND

New conduction disturbances are the most frequent complication of TAVI, often necessitating PPM implantation before hospital discharge.

METHODS

We performed an observational cohort analysis of the UK TAVI registry (2007-2015). Primary and secondary endpoints were 30-day post-discharge all-cause mortality and long-term survival, respectively.

RESULTS

Of 8,651 procedures, 6,815 complete datasets were analyzed. A PPM at hospital discharge, irrespective of when implantation occurred (PPM 1.68% [22/1309] vs. no PPM 1.47% [81/5506], odds ratio [OR] 1.14, 95% confidence interval [CI] 0.71-1.84; p = .58), or a PPM implanted peri- or post-TAVI only (PPM 1.44% [11/763] vs. no PPM 1.47% [81/5506], OR 0.98 [0.51-1.85]; p = .95) did not significantly reduce the primary endpoint. Patients with a PPM at discharge were older, male, had right bundle branch block at baseline, were more likely to have received a first-generation self-expandable prosthesis and had experienced more peri- and post-procedural complications including bailout valve-in-valve rescue, bleeding and acute kidney injury. A Cox proportional hazards model demonstrated significantly reduced long-term survival in all those with a PPM, irrespective of implantation timing (hazard ratio [HR] 1.14 [1.02-1.26]; p = .019) and those receiving a PPM only at the time of TAVI (HR 1.15 [1.02-1.31]; p = .032). The reasons underlying this observation warrant further investigation.

CONCLUSIONS

A PPM did not confer a survival advantage in the first 30 days after hospital discharge following TAVI.

Predicting the Need For Permanent Pacing After Implantation of the Repositionable Lotus Transcatheter Aortic Valve

BACKGROUND

The need for permanent pacemaker implantation (PPI) following transcatheter aortic valve implantation (TAVI) is a recognized complication due to compression of the cardiac conduction system. PPI rates vary according to type of TAVI device, implantation technique, and patient-related factors.

METHODS

We analyzed the baseline characteristics, and then the preprocedure and daily postprocedure electrocardiograms (ECGs) of 101 consecutive patients who underwent TAVI using the Lotus valve (Boston Scientific) between 2013 and 2015.

RESULTS

Mean patient age was 81.7 ± 7.7 years, 56% were male. and 21 patients were excluded because of baseline atrial fibrillation or a pre-existing PPI. Of the remaining 80 patients, a total of 28 (35%) underwent PPI at a mean 2.7 days after TAVI. There were no differences in development of new left bundle-branch block between the two groups (65% PPI group vs 74% no-PPI group; P=.37). The initial PR interval did not differ between groups (183 ms PPI group vs 184 ms no-PPI group). The PR interval increased by day 1 post procedure (232 ms PPI group vs 195 ms no-PPI group; P<.01) and day 2 (267 ms PPI group vs 211 ms no-PPI group; P<.05).

CONCLUSIONS

Patients with a PR interval ≤230 ms on day 1 or ≤260 ms on day 2 post TAVI using the Lotus device are at very low risk of requiring PPI, irrespective of the presence of left bundle-branch block, and can be safely discharged without prolonged monitoring.

In-hospital stroke after transcatheter aortic valve implantation: A UK observational cohort analysis

OBJECTIVES

We sought to identify baseline demographics and procedural factors that might independently predict in-hospital stroke following transcatheter aortic valve implantation (TAVI).

BACKGROUND

Stroke is a recognized, albeit infrequent, complication of TAVI. Established predictors of procedure-related in-hospital stroke; however, remain poorly defined.

METHODS

We conducted an observational cohort analysis of the multicenter UK TAVI registry. The primary outcome measure was the incidence of in-hospital stroke.

RESULTS

A total of 8,652 TAVI procedures were performed from 2007 to 2015. There were 205 in-hospital strokes reported by participating centers equivalent to an overall stroke incidence of 2.4%. Univariate analysis showed that the implantation of balloon-expandable valves caused significantly fewer strokes (balloon-expandable 96/4,613 [2.08%] vs. self-expandable 95/3,272 [2.90%]; p = .020). After multivariable analysis, prior cerebrovascular disease (CVD) (odds ratio [OR] 1.51, 95% confidence interval [CI 1.05-2.17]; p = .03), advanced age at time of operation (OR 1.02 [0.10-1.04]; p = .05), bailout coronary stenting (OR 5.94 [2.03-17.39]; p = .008), and earlier year of procedure (OR 0.93 [0.87-1.00]; p = .04) were associated with an increased in-hospital stroke risk. There was a reduced stroke risk in those who had prior cardiac surgery (OR 0.62 [0.41-0.93]; p = .01) and a first-generation balloon-expandable valve implanted (OR 0.72 [0.53-0.97]; p = .03). In-hospital stroke significantly increased 30-day (OR 5.22 [3.49-7.81]; p < .001) and 1-year mortality (OR 3.21 [2.15-4.78]; p < .001).

CONCLUSIONS

In-hospital stroke after TAVI is associated with substantially increased early and late mortality. Factors independently associated with in-hospital stroke were previous CVD, advanced age, no prior cardiac surgery, and deployment of a predominantly first-generation self-expandable transcatheter heart valve.

Ecological succession in the vaginal microbiota during pregnancy and birth

The mother's vaginal microbiota represents the first microbes to which a child is exposed when delivered vaginally. However, little is known about the composition and development of the vaginal microbiota during pregnancy and birth. Here, we analyzed the vaginal microbiota of 57 women in pregnancy week 24, 36 and at birth after rupture of membranes but before delivery, and further compared the composition with that of the gut and airways of the 1-week-old child. The vaginal community structure had dramatic changes in bacterial diversity and taxonomic distribution, yet carried an individual-specific signature. The relative abundance of most bacterial taxa increased stepwise from week 24 of pregnancy until birth, with a gradual decline of Lactobacillus. Mother-to-child vertical transfer, as suggested by sharing, was modest, with the strongest transfer being for Clostridiales followed by Lactobacillales and Enterobacteriales. In conclusion, late gestation is associated with an increase in maternal vaginal microbiota diversity, and vaginal bacteria at birth only modestly predict the composition of the neonatal microbiota.

Transcatheter aortic valve implantation via surgical subclavian versus direct aortic access: A United Kingdom analysis

BACKGROUND

Surgical subclavian (SC) and direct aortic (DA) access are established alternatives to the default transfemoral route for transcatheter aortic valve implantation (TAVI). We sought to find differences in survival and procedure-related outcomes after SC- versus DA-TAVI.

METHODS

We performed an observational cohort analysis of cases prospectively uploaded to the UK TAVI registry. To ensure the most contemporaneous comparison, the analysis focused on SC and DA procedures performed from 2013 to 2015.

RESULTS

Between January 2013 and July 2015, 82 (37%) SC and 142 (63%) DA cases were performed that had validated 1-year life status. Multivariable regression analysis showed procedure duration was longer for SC cases (SC 193.5 ± 65.8 vs. DA 138.4 ± 57.7 min; p < .01) but length of hospital stay was shorter (SC 8.6 ± 9.5 vs. DA 11.9 ± 10.8 days; p = .03). Acute kidney injury was observed less frequently after SC cases (odds ratio [OR] 0.35, 95% confidence interval [CI 0.12-0.96]; p = .042) but vascular access site-related complications were more common (OR 9.75 [3.07-30.93]; p < .01). Procedure-related bleeding (OR 0.54 [0.24-1.25]; p = .15) and in-hospital stroke rate (SC 3.7% vs. DA 2.1%; p = .67) were similar. There were no significant differences in in-hospital (SC 2.4% vs. DA 4.9%; p = .49), 30-day (SC 2.4% vs. DA 4.2%; p = .71) or 1-year (SC 14.5% vs. DA 21.9%; p = .344) mortality.

CONCLUSIONS

Surgical subclavian and direct aortic approaches can offer favourable outcomes in appropriate patients. Neither access modality conferred a survival advantage but there were significant differences in procedural metrics that might influence which approach is selected.

Thrombosis of a Percutaneous Transcatheter Mitral Valve Implant and Its Treatment

Bioprosthetic heart valves do not usually require formal anticoagulation as they are less thrombogenic than their mechanical counterparts. However, valve thrombosis has been reported after both transcatheter and surgical aortic bioprosthesis implantation. Short-term anticoagulation after surgical bioprosthesis implantation is often recommended while endothelialisation of the prosthesis takes place, particularly for mitral valve implants. There have been no reports of tissue heart valve thrombosis in transcatheter mitral valve replacement. We describe our experience and successful treatment of such a case.

Percutaneous coronary angioplasty versus coronary artery bypass grafting in the treatment of unprotected left main stenosis: updated 5-year outcomes from the randomised, non-inferiority NOBLE trial

BACKGROUND

Percutaneous coronary intervention (PCI) is increasingly used in revascularisation of patients with left main coronary artery disease in place of the standard treatment, coronary artery bypass grafting (CABG). The NOBLE trial aimed to evaluate whether PCI was non-inferior to CABG in the treatment of left main coronary artery disease and reported outcomes after a median follow-up of 3·1 years. We now report updated 5-year outcomes of the trial.

METHODS

The prospective, randomised, open-label, non-inferiority NOBLE trial was done at 36 hospitals in nine northern European countries. Patients with left main coronary artery disease requiring revascularisation were enrolled and randomly assigned (1:1) to receive PCI or CABG. The primary endpoint was major adverse cardiac or cerebrovascular events (MACCE), a composite of all-cause mortality, non-procedural myocardial infarction, repeat revascularisation, and stroke. Non-inferiority of PCI to CABG was defined as the upper limit of the 95% CI of the hazard ratio (HR) not exceeding 1·35 after 275 MACCE had occurred. Secondary endpoints included all-cause mortality, non-procedural myocardial infarction, and repeat revascularisation. Outcomes were analysed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT01496651.

FINDINGS

Between Dec 9, 2008, and Jan 21, 2015, 1201 patients were enrolled and allocated to PCI (n=598) or CABG (n=603), with 17 subsequently lost to early follow-up. 592 patients in each group were included in this analysis. At a median of 4·9 years of follow-up, the predefined number of events was reached for adequate power to assess the primary endpoint. Kaplan-Meier 5-year estimates of MACCE were 28% (165 events) for PCI and 19% (110 events) for CABG (HR 1·58 [95% CI 1·24-2·01]); the HR exceeded the limit for non-inferiority of PCI compared to CABG. CABG was found to be superior to PCI for the primary composite endpoint (p=0·0002). All-cause mortality was estimated in 9% after PCI versus 9% after CABG (HR 1·08 [95% CI 0·74-1·59]; p=0·68); non-procedural myocardial infarction was estimated in 8% after PCI versus 3% after CABG (HR 2·99 [95% CI 1·66-5·39]; p=0·0002); and repeat revascularisation was estimated in 17% after PCI versus 10% after CABG (HR 1·73 [95% CI 1·25-2·40]; p=0·0009).

INTERPRETATION

In revascularisation of left main coronary artery disease, PCI was associated with an inferior clinical outcome at 5 years compared with CABG. Mortality was similar after the two procedures but patients treated with PCI had higher rates of non-procedural myocardial infarction and repeat revascularisation.

FUNDING

Biosensors.