Reweighting and validation of the hospital frailty risk score using electronic health records in Germany: a retrospective observational study.

BACKGROUND: In the hospital setting, frailty is a significant risk factor, but difficult to measure in clinical practice. We propose a reweighting of an existing diagnoses-based frailty score using routine data from a tertiary care teaching hospital in southern Germany. METHODS: The dataset includes patient characteristics such as sex, age, primary and secondary diagnoses and in-hospital mortality. Based on this information, we recalculate the existing Hospital Frailty Risk Score. The cohort includes patients aged ≥ 75 and was divided into a development cohort (admission year 2011 to 2013, N = 30,525) and a validation cohort (2014, N = 11,202). A limited external validation is also conducted in a second validation cohort containing inpatient cases aged ≥ 75 in 2022 throughout Germany (N = 491,251). In the development cohort, LASSO regression analysis was used to select the most relevant variables and to generate a reweighted Frailty Score for the German setting. Discrimination is assessed using the area under the receiver operating characteristic curve (AUC). Visualization of calibration curves and decision curve analysis were carried out. Applicability of the reweighted Frailty Score in a non-elderly population was assessed using logistic regression models. RESULTS: Reweighting of the Frailty Score included only 53 out of the 109 frailty-related diagnoses and resulted in substantially better discrimination than the initial weighting of the score (AUC = 0.89 vs. AUC = 0.80, p < 0.001 in the validation cohort). Calibration curves show a good agreement between score-based predictions and actual observed mortality. Additional external validation using inpatient cases aged ≥ 75 in 2022 throughout Germany (N = 491,251) confirms the results regarding discrimination and calibration and underlines the geographic and temporal validity of the reweighted Frailty Score. Decision curve analysis indicates that the clinical usefulness of the reweighted score as a general decision support tool is superior to the initial version of the score. Assessment of the applicability of the reweighted Frailty Score in a non-elderly population (N = 198,819) shows that discrimination is superior to the initial version of the score (AUC = 0.92 vs. AUC = 0.87, p < 0.001). In addition, we observe a fairly age-stable influence of the reweighted Frailty Score on in-hospital mortality, which does not differ substantially for women and men. CONCLUSIONS: Our data indicate that the reweighted Frailty Score is superior to the original Frailty Score for identification of older, frail patients at risk for in-hospital mortality. Hence, we recommend using the reweighted Frailty Score in the German in-hospital setting.

Transcatheter aortic valve replacement in Germany with need for a surgical bailout.

BACKGROUND: In transcatheter aortic valve replacement (TAVR), complications may force the need for a surgical bailout, but knowledge is rare about outcomes in Germany. METHODS: Using national health records, we investigated all TAVR in German hospitals between 2007 and 2020, focusing on 2018-2020. We extracted data on those interventions with need for a surgical bailout. RESULTS: A total of 159,643 TAVR were analyzed, with an overall rate of surgical bailout of 2.30 %, an overall in-hospital mortality of 3.85 %, and in-hospital mortality in case of bailout of 16.51 %. The number of all annual TAVR procedures increased substantially (202 to 22,972), with the rate of surgical bailout declining from 27.23 to 0.61 % and overall mortality from 11.39 to 2.29 %. However, in-hospital mortality after bailout was still high (28.37 % in 2020). The standardized rates of overall mortality and surgical bailout between 2018 and 2020 were significantly lower for balloon-expandable and self-expanding transfemoral TAVR than for transapical TAVR after risk adjustment [transapical/transfemoral balloon-expandable/transfemoral self-expanding TAVR: in-hospital mortality: 5.66 % (95 % CI 4.81 %; 6.52 %)/2.30 % (2.03 %; 2.57 %)/2.32 % (2.07 %; 2.57 %); surgical bailout: 2.33 % (1.68 %; 2.97 %)/0.79 % (0.60 %; 0.98 %)/0.42 % (0.31 %; 0.53 %)]. Coronary artery disease [risk-adjusted OR = 1.50 (1.21; 1.85), p < 0.001] and atrial fibrillation [OR = 1.29 (1.07; 1.57), p = 0.009] were found to be the main risk factors for bailout. CONCLUSIONS: Rates of TAVR with need for a surgical bailout and overall in-hospital mortality have declined noticeably over the years in Germany. However, the outcomes are still unfavorable after surgical bailout, as in-hospital mortality is continuously high. We present risk factors for surgical bailout to improve preparation of subsequent measures. It must be a major goal to further reduce the rate of surgical bailouts in the future.

Comparing balloon-expandable and self-expanding transfemoral transcatheter aortic valve replacement based on subgroups in Germany 2019/2020.

BACKGROUND: Previously, overall comparable outcomes were seen for balloon-expandable (BE) or self-expanding (SE) transfemoral transcatheter aortic valve replacement (TAVR). However, subgroup analyses based on large case numbers are still needed. METHODS: German national data of all BE and SE transfemoral TAVR treating aortic valve stenosis in 2019 and 2020 were analysed. We then compared different outcomes and performed a subgroup analysis for the endpoint in-hospital mortality. RESULTS: Overall, 46,243 TAVR were analysed, 19,910 BE, and 26,333 SE. Patients in the SE group had a significantly higher logistic EuroSCORE (13.61 vs 12.66%, p < 0.001), age (81.55 vs 79.99a, p < 0.001), and proportion of women (54.82 vs 40.06%, p < 0.001). Both groups showed a similar in-hospital mortality with 2.37% in BE and 2.35% in SE (p = 0.916). In-hospital mortality also did not differ significantly after risk adjustment (OR = 0.98 [0.86, 1.13], p = 0.799). Patients in the SE group had a significantly lower risk of major bleeding (OR = 0.83 [0.73, 0.95], p = 0.006), but a significantly higher risk of stroke (OR = 1.38 [1.19, 1.59], p < 0.001), delirium (OR = 1.15 [1.06, 1.24], p = 0.001), and permanent pacemaker implantation (OR = 1.29 [1.21, 1.37], p < 0.001). In the subgroup analysis of in-hospital mortality, there were no significant differences in any of the observed subgroups (age < 75/75-79/80-84/ ≥ 85a, logistic EuroSCORE < 4/4- < 9/ ≥ 9, gender, NYHA III/IV, previous CABG, peripheral vascular disease, COPD, pulmonary hypertension, renal disease GFR < 30 ml/min, and diabetes mellitus). CONCLUSION: In the direct comparison of balloon-expandable and self-expanding TAVR, there are no differences for in-hospital mortality in subgroups.

Center Volumes Correlate with Likelihood of Stent Implantation in German Coronary Angiography.

Aims: Literature on percutaneous coronary intervention (PCI) stated an inverse relationship between hospital volume and mortality, but the effects on other characteristics are unclear. Methods: Using German national records, all coronary angiographies with coronary artery disease in 2017 were identified. We applied risk-adjustment to account for differences in population characteristics. Results: Of overall 528,188 patients, 55.22% received at least one stent, with on average 1.01 stents implanted in all patients. Based on those patients who received at least one stent, this corresponds to an average number of 1.82 stents. In-hospital mortality across all patients was 2.93%, length of hospital stay was 6.46 days, and mean reimbursement was €5,531. There were comparatively more emergency admissions in low volume centers and more complex cases (3-vessel disease, left main stenosis, and in-stent stenosis) in high volume centers. In multivariable regression analysis, volume and likelihood of stent implantation (p=0.003) as well as number of stents (p=0.020) were positively correlated. No relationship was seen for in-hospital mortality (p=0.105), length of stay (p=0.201), and reimbursement (p=0.108). Nonlinear influence of volume suggests a ceiling effect: In hospitals with ≤100 interventions, likelihood and number of implanted stents are lowest (∼34% and 0.6). After that, both rise steadily until a volume of 500 interventions. Finally, both remain stable in the categories of over 500 interventions (∼60% and 1.1). Conclusion: In PCI, lower volume centers contribute to emergency care. Higher volume centers treat more complex cases and show a higher likelihood of stent implantations, with a stable safety.

Treatment of pure aortic regurgitation using surgical or transcatheter aortic valve replacement between 2018 and 2020 in Germany.

Background: In pure aortic regurgitation, transcatheter aortic valve replacement (TAVR) is not yet used on a regular base. Due to constant development of TAVR, it is necessary to analyze current data. Methods: By use of health records, we analyzed all isolated TAVR or surgical aortic valve replacements (SAVR) for pure aortic regurgitation between 2018 and 2020 in Germany. Results: 4,861 procedures-4,025 SAVR and 836 TAVR-for aortic regurgitation were identified. Patients treated with TAVR were older, showed a higher logistic EuroSCORE, and had more pre-existing diseases. While results indicate a slightly higher unadjusted in-hospital mortality for transapical TAVR (6.00%) vs. SAVR (5.71%), transfemoral TAVR showed better outcomes, with self-expanding compared to balloon-expandable transfemoral TAVR having significantly lower in-hospital mortality (2.41% vs. 5.17%; p = 0.039). After risk adjustment, balloon-expandable as well as self-expanding transfemoral TAVR were associated with a significantly lower mortality vs. SAVR (balloon-expandable: risk adjusted OR = 0.50 [95% CI 0.27; 0.94], p = 0.031; self-expanding: OR = 0.20 [0.10; 0.41], p < 0.001). Furthermore, the observed in-hospital outcomes of stroke, major bleeding, delirium, and mechanical ventilation >48 h were significantly in favor of TAVR. In addition, TAVR showed a significantly shorter length of hospital stay compared to SAVR (transapical: risk adjusted Coefficient = -4.75d [-7.05d; -2.46d], p < 0.001; balloon-expandable: Coefficient = -6.88d [-9.06d; -4.69d], p < 0.001; self-expanding: Coefficient = -7.22 [-8.95; -5.49], p < 0.001). Conclusions: TAVR is a viable alternative to SAVR in the treatment of pure aortic regurgitation for selected patients, showing overall low in-hospital mortality and complication rates, especially with regard to self-expanding transfemoral TAVR.

Impact of the COVID-19 pandemic on aortic valve replacement procedures in Germany.

BACKGROUND: COVID-19 has caused the deferral of millions of elective procedures, likely resulting in a backlog of cases. We estimate the number of postponed surgical aortic valve replacement (sAVR) and transcatheter aortic valve replacement (TAVR) procedures during the first two waves of the COVID-19 pandemic in Germany. METHODS: Using German national records, all isolated TAVR and sAVR procedures between 2007 and 2020 were identified. Using weekly TAVR and sAVR procedures between 2017 and 2019, we created a forecast for 2020 and compared it with the observed number of procedures in 2020. RESULTS: In Germany, a total of 225,398 isolated sAVR and 159,638 isolated TAVR procedures were conducted between 2007 and 2020 that were included in our analysis. The reduction in all AVR procedures (sAVR and TAVR) for the entire year 2020 was 19.07% (95%CI: 15.19-22.95%). During the first wave of the pandemic (week 12-21), the mean weekly reduction was 32.06% (23.44-40.68%) and during the second wave of the pandemic (week 41-52), the mean weekly reduction was 25.58% (14.19-36.97%). The number of sAVR procedures decreased more than the number of TAVR procedures (24.63% vs. 16.42% for the entire year 2020). CONCLUSION: The first year of the COVID-19 pandemic saw a substantial postponing of AVR procedures in Germany. Postponing was higher for sAVR than for TAVR procedures and less pronounced during the second wave of the COVID-19 pandemic.

COVID-19 pandemic affects STEMI numbers and in-hospital mortality: results of a nationwide analysis in Germany.

BACKGROUND: The COVID-19 pandemic led to extensive restrictions in Germany in 2020, including the postponement of elective interventions. We examined the impact on ST-elevation myocardial infarction (STEMI) as an acute and non-postponable disease. METHODS: Using German national records, all STEMI between 2017 and 2020 were identified. Using the number of STEMI cases between 2017 and 2019, we created a forecast for 2020 and compared it with the observed number of STEMI in 2020. RESULTS: From 2017 to 2020, 248,062 patients were treated for STEMI in Germany. Mean age was 65.21 years and 28.36% were female. When comparing forecasted and observed STEMI in 2020, a correlation can be seen: noticeable fewer STEMI were treated in those weeks respectively months with an increasing COVID-19 hospitalization rate (monthly percentage decrease in STEMI: March - 14.85%, April - 13.39%, November - 11.92%, December - 22.95%). At the same time, the crude in-hospital mortality after STEMI increased significantly at the peaks of the first and second waves (relative risk/RR of monthly in-hospital mortality: April RR = 1.11 [95% CI 1.02; 1.21], November RR = 1.13 [1.04; 1.24], December RR = 1.16 [1.06; 1.27]). CONCLUSION: The COVID-19 pandemic led to a noticeable decrease in the number of STEMI interventions in Germany at the peaks of the first and second waves in 2020, corresponding to an increase in COVID-19 hospitalizations. At the same time, in-hospital mortality after STEMI increased significantly in these phases. Impact of the COVID-19 pandemic on STEMI numbers and in-hospital mortality in Germany. Relative difference between forecasted and observed STEMI numbers (above figure), the relative risk of in-hospital mortality (middle figure) as well as number of new hospital admissions for COVID-19 per million inhabitants according to Roser et al.27 (bottom figure).

Hospital intervention volume affects outcomes of emergency transcatheter aortic valve implantations in Germany.

The literature has shown an inverse volume-outcome relationship for transcatheter aortic valve implantation (TAVI). However, little is known about emergency admissions in Germany. Using German national electronic health records, we identified all isolated balloon-expandable and self-expanding transfemoral TAVI in 2018. The focus was on those patients with emergency admission. 17,295 patients were treated with TAVI, including 1682 emergency cases. 49.2% of the emergency admissions were female, the mean age was 81.2 years and the logistic EuroSCORE was 23.3%. The percentage of emergency cases was higher in lower volume than in higher volume centers (p < 0.001): In detail, centers performing < 50 TAVI showed an emergency admission rate of ~ 15%, those with > 200 TAVI a rate of ~ 11%. After propensity score adjustment, analyzing the outcomes for an increase in volume per 10 emergency admissions, higher volume centers showed significantly better outcomes regarding in-hospital mortality (OR = 0.872, p = 0.043), major bleeding (OR = 0.772, p = 0.001), stroke (OR = 0.816, p = 0.044), mechanical ventilation > 48 h (OR = 0.749, p = 0.001), length of hospital stay (risk adjusted difference in days of hospitalization per 10 emergency admissions: - 1.01 days, p < 0.001), and reimbursement (risk adjusted difference in reimbursement per 10 emergency admissions: -€314.89, p < 0.001). Results were not significant for acute kidney injury (OR = 0.951, p = 0.104), postoperative delirium (OR = 0.975, p = 0.480), and permanent pacemaker implantation (OR = 1.010, p = 0.732). In conclusion, regarding transfemoral TAVI, the percentage of emergency cases was higher in lower volume centers in Germany. However, higher volume centers show significantly better outcomes for in-hospital mortality and complication rates as well as resource utilization parameters.

Impact of Procedure Volume on the Outcomes of Surgical Aortic Valve Replacement.

BACKGROUND: Literature demonstrated that procedure volumes affect outcomes of patients undergoing transcatheter aortic valve implantation. We evaluated the outcomes of surgical aortic valve replacement. METHODS: All isolated surgical aortic valve replacement procedures in Germany in 2017 were identified. Hospitals were divided into five groups from ≤25 (very low volume) until >100 (very high volume) annual procedures. RESULTS: In 2017, 5,533 patients underwent isolated surgical aortic valve replacement. All groups were of comparable risk (logistic EuroSCORE, 5.12-4.80%) and age (66.6-68.1 years). In-hospital mortality and complication rates were lowest in the very high-volume group. Multivariable logistic regression analyses showed no significant volume-outcome relationship for in-hospital mortality, stroke, postoperative delirium, and mechanical ventilation > 48 hours. Regarding acute kidney injury, patients in the very high-volume group were at lower risk than those in the very low volume group (odds ratio [OR] = 0.53, p = 0.04). Risk factors for in-hospital mortality were previous cardiac surgery (OR = 5.75, p < 0.001), high-grade renal disease (glomerular filtration rate < 15 mL/min, OR = 5.61, p = 0.002), surgery in emergency cases (OR = 2.71, p = 0.002), and higher grade heart failure (NYHA [New York Heart Association] III/IV; OR = 1.80, p = 0.02). Risk factors for all four complication rates were atrial fibrillation and diabetes mellitus. CONCLUSION: Patients treated in very low volume centers (≤25 operations/year) had a similar risk regarding in-hospital mortality and most complications compared with very high-volume centers (>100 operations/year). Only in the case of acute kidney injury, very high-volume centers showed better outcomes than very low volume centers. Therefore, surgical aortic valve replacement can be performed safely independent of case volume.

Coronary artery bypass grafting versus stent implantation in patients with chronic coronary syndrome and left main disease: insights from a register throughout Germany.

BACKGROUND: Recent randomized controlled trials have sparked debate about the optimal treatment of patients suffering from left main coronary artery disease. The present study analyzes outcomes of left main stenting versus coronary bypass grafting (CABG) in a nationwide registry in patients with chronic coronary syndrome (CCS). METHODS: All cases suffering from CCS and left main coronary artery disease treated either with CABG or stent, were identified within the database of the German bureau of statistics. Logistic or linear regression models were used with 20 baseline patient characteristics as potential confounders to compare both regimens. RESULTS: In 2018, 1318 cases with left main stenosis were treated with CABG and 8,920 with stent. Patients assigned for stenting were older (72.58 ± 9.87 vs. 68.63 ± 9.40, p < 0.001) and at higher operative risk, as assessed by logistic EuroSCORE (8.77 ± 8.45 vs. 4.85 ± 4.65, p < 0.001). After risk adjustment, no marked differences in outcomes were found for in-hospital mortality and stroke (risk adjusted odds ratio (aOR) for stent instead of CABG: aOR mortality: 1.08 [95% CI 0.66; 1.78], p = 0.748; aOR stroke: 0.59 [0.27; 1.32], p = 0.199). Stent implantation was associated with a reduced risk of relevant bleeding (aOR 0.38 [0.24; 0.61], p < 0.001), reduced prolonged ventilation time (aOR 0.54 [0.37 0.79], p = 0.002), and postoperative delirium (aOR 0.16 [0.11; 0.22], p < 0.001). Furthermore, stent implantation was associated with shorter hospital stay (- 6.78 days [- 5.86; - 7.71], p < 0.001) and lower costs (- €10,035 [- €11,500; - €8570], p < 0.001). CONCLUSION: Left main stenting is a safe and effective treatment option for CCS-patients suffering from left main coronary artery disease at reasonable economic cost. Coronary artery bypass grafting versus stent implantation in patients with chronic coronary syndrome and left main disease: insights from a register throughout Germany. All cases with chronic coronary syndrome and left main stenosis treated in 2018 in Germany either with left main stenting or coronary bypass grafting were extracted from a nation-wide database. In-hospital outcomes were compared after logistic regression analysis.

Outcomes of female and male patients suffering from coronary artery disease: A nation-wide registry of patients admitted as emergency.

ABSTRACT: Presentation and mortality of coronary artery disease (CAD) substantially differs in both sexes. Most of the existing data analyzing sex differences is older than 10 years and mostly was retrieved in clinical trials, which are potentially structured with a bias against the inclusion of women, leading to a potential selection-bias. Meanwhile, with better diagnostic and therapeutic options, actual data analyzing sex differences in emergency CAD patients is rare.Data on all emergency case numbers with CAD diagnosis in Germany 2017 was retrieved from the German Institute for Medical Documentation and Information. DRG, OPS, and ICD codes were used to determine comorbidities, in-hospital course, and outcome. Competing risk regression analysis for in-hospital mortality was performed analyzing age, European System for Cardiac Operative Risk Evaluation (EuroSCORE), severity of CAD, clinical presentation type and sex.264,742 patients were included. Female patients were older and had more comorbidities. Three-vessel CAD was significantly less present in female patients (36.5% vs 47.5%; P < .001). After adjusting for age, EuroSCORE and severity of CAD, female sex was an independent predictor of lower in-hospital mortality (subdistribution hazard ratio [sHR] 0.94, 95% CI: 0.90-0.98, P = .002) in the whole cohort and in non-ST-segment elevation myocardial infarction (NSTEMI) patients (sHR 0.85, 95% CI: 0.79-0.92, P < .001), whereas in ST-segment elevation myocardial infarction (STEMI) patients, female sex was associated with a higher in-hospital mortality (sHR 1.07, 95% CI: 1.01-1.14, P = .029).In all patients admitted as emergency with CAD diagnosis and in all NSTEMI patients, female sex is protective, whereas in STEMI patients, females show a higher in-hospital mortality risk.

In-hospital outcomes of self-expanding and balloon-expandable transcatheter heart valves in Germany.

INTRODUCTION: The effect of valve type on outcomes in transfemoral transcatheter aortic valve replacement (TF-TAVR) has recently been subject of debate. We investigate outcomes of patients treated with balloon-expanding (BE) vs. self-expanding (SE) valves in in a cohort of all these procedures performed in Germany in 2018. METHODS: All patients receiving TF-TAVR with either BE (N = 9,882) or SE (N = 7,413) valves in Germany in 2018 were identified. In-hospital outcomes were analyzed for the endpoints in-hospital mortality, major bleeding, stroke, acute kidney injury, postoperative delirium, permanent pacemaker implantation, mechanical ventilation > 48 h, length of hospital stay, and reimbursement. Since patients were not randomized to the two treatment options, logistic or linear regression models were used with 22 baseline patient characteristics and center-specific variables as potential confounders. As a sensitivity analysis, the same confounding factors were taken into account using the propensity score methods (inverse probability of treatment weighting). RESULTS: Baseline characteristics differed substantially, with higher EuroSCORE (p < 0.001), age (p < 0.001) and rate of female sex (p < 0.001) in SE treated patients. After risk adjustment, no marked differences in outcomes were found for in-hospital mortality [risk adjusted odds ratio (aOR) for SE instead of BE 0.94 (96% CI 0.76;1.17), p = 0.617] major bleeding [aOR 0.91 (0.73;1.14), p = 0.400], stroke [aOR 1.13 (0.88;1.46), p = 0.347], acute kidney injury [OR 0.97 (0.85;1.10), p = 0.621], postoperative delirium [aOR 1.09 (0.96;1.24), p = 0.184], mechanical ventilation > 48 h [aOR 0.98 (0.77;1.25), p = 0.893], length of hospital stay (risk adjusted difference in days of hospitalization (SE instead of BE): - 0.05 [- 0.34;0.25], p = 0.762) and reimbursement [risk adjusted difference in reimbursement (SE instead of BE): - €72 (- €291;€147), p = 0.519)] There is, however, an increased risk of PPI for SE valves (aOR 1.27 [1.15;1.41], p < 0.001). Similar results were found after application of propensity score adjustment. CONCLUSIONS: We find broadly equivalent outcomes in contemporary TF-TAVR procedures, regardless of the valve type used. Incidence of major complications is very low for both types of valve.

Transapical aortic valve replacement versus surgical aortic valve replacement: A subgroup analyses for at-risk populations.

BACKGROUND: If the transfemoral access is not feasible, a transapical access or surgical aortic valve replacement (SAVR) are alternatives for patients with aortic valve stenosis. OBJECTIVES: To identify patient groups who benefit from SAVR or transapical transcatheter aortic valve replacement (TA-TAVR), we compared in-hospital outcomes of patients in a nationwide dataset. METHODS: We identified 19,016 isolated SAVR and 6432 TA-TAVR performed in Germany from 2014 to 2016. We adjusted for risk factors using a covariate- and propensity-adjusted analysis. RESULTS: Patients undergoing TA-TAVR were older, had more comorbidities, and accordingly greater estimated operative risk (logistic European System for Cardiac Operative Risk Evaluation 5.3 vs 17.0, P < .001). However, adjusted risk for in-hospital complications such as stroke, acute kidney injury, relevant bleeding, and prolonged mechanical ventilation >48 hours was lower in patients undergoing TA-TAVR (all P < .001). When we compared in-hospital mortality of all patients undergoing either TA-TAVR or SAVR, neither treatment strategy had a clear advantage (covariate-adjusted odds ratio [caOR], 1.13, P = .251; propensity-adjusted OR [paOR], 1.12, P = .309). Two patient subgroups seem to benefit more from SAVR than TA-TAVR: patients <75 years (caOR, 1.29, P = .237; paOR, 2.12, P = .001) and those with European System for Cardiac Operative Risk Evaluation 4-9 (caOR, 1.32, P = .114; paOR, 1.43, P = .041). Female patients had a tendency toward lower risk for in-hospital mortality when undergoing SAVR (caOR, 1.42, P = .030). In patients with chronic renal failure, TA-TAVR was superior (caOR, 0.56, P = .039, P = .040). CONCLUSIONS: Patients <75 years and those at low operative risk who underwent SAVR had lower in-hospital mortality than those undergoing TA-TAVR. Patients with chronic renal failure who underwent TA-TAVR had lower in hospital mortality than those that underwent SAVR.

Outcomes of transcatheter aortic valve implantations in high-volume or low-volume centres in Germany.

OBJECTIVE: Transcatheter aortic valve implantation (TAVI) is the most common aortic valve replacement in Germany. Since 2015, to ensure high-quality procedures, hospitals in Germany and other countries that meet the minimum requirement of 50 interventions per centre are being certified to perform TAVI. This study analyses the impact of these requirements on case number and in-hospital outcomes. METHODS: All isolated TAVI procedures and in-hospital outcomes between 2008 and 2016 were identified by International Classification of Diseases (ICD) and the German Operation and Procedure Classification codes. RESULTS: 73 467 isolated transfemoral and transapical TAVI procedures were performed in Germany between 2008 and 2016. During this period, the number of TAVI procedures per year rose steeply, whereas the overall rates of hospital mortality and complications declined. In 2008, the majority of procedures were performed in hospitals with fewer than 50 cases per year (54.63%). Until 2014, the share of patients treated in low-volume centres constantly decreased to 5.35%. After the revision of recommendations, it further declined to 1.99%. In the 2 years after the introduction of the minimum requirements on case numbers, patients were at decreased risk for in-hospital mortality when treated in a high-volume centre (risk-adjusted OR 0.62, p=0.012). The risk for other in-hospital outcomes (stroke, permanent pacemaker implantation and bleeding events) did not differ after risk adjustment (p=0.346, p=0.142 and p=0.633). CONCLUSION: A minimum volume of 50 procedures per centre and year appears suitable to allow for sufficient routine and thus better in-hospital outcomes, while ensuring nationwide coverage of TAVI procedures.

Volume-outcome relationship in transcatheter aortic valve implantations in Germany 2008-2014: a secondary data analysis of electronic health records.

OBJECTIVES: We examine the volume-outcome relationship in isolated transcatheter aortic valve implantations (TAVI). Our interest was whether the volume-outcome relationship for TAVI exists on the centre level, whether it occurs equally for different outcomes and how it develops over time. DESIGN: Secondary data analysis of electronic health records. The comprehensive German Federal Bureau of Statistics Diagnosis Related Groups database was queried for data on all isolated TAVI procedures performed in Germany between 2008 and 2014. Logistic and linear regression analyses were carried out. Risk adjustment was applied using a predefined set of patient characteristics to account for differences in the risk factor composition of the patient populations between centres and over time. Centres performing TAVI were stratified into groups performing <50, 50-99 and ≥100 procedures per year. SETTING: Germany 2008-2014. PARTICIPANTS: All patients undergoing isolated TAVI in the observation period. INTERVENTIONS: None. PRIMARY AND SECONDARY OUTCOME MEASURES: In-hospital mortality, bleeding, stroke, probability of ventilation >48 hours, length of hospital stay and reimbursement. RESULTS: Between 2008 and 2014, a total of 43 996 TAVI procedures were performed in 113 different centres in Germany with a total of 2532 cases of in-hospital mortality. Risk-adjusted in-hospital mortality decreases over the years and is lower the higher the annual procedure volume at the centre is. The magnitude of the latter effect declines over the observation period. Our results indicate a ceiling effect in the volume-outcome relationship: the volume-outcome relationship is eminent in circumstances of relatively unfavourable outcomes. Alongside improving outcomes, however, the volume-outcome relationship decreases. Also, a volume-outcome relationship seems to be absent in circumstances of constantly low event rates. CONCLUSIONS: The hypothesised volume-outcome relationship for TAVI exists but diminishes and may disappear over time. This should be taken into account when considering mandatory minimum thresholds.