CRT Survey Scientific Committee. European cardiac resynchronization therapy survey: rationale and design

Machine learning-based prediction of 1-year all-cause mortality in patients undergoing CRT implantation: validation of the SEMMELWEIS-CRT score in the European CRT Survey I dataset

Aims

We aimed to externally validate the SEMMELWEIS-CRT score for predicting 1-year all-cause mortality in the European Cardiac Resynchronization Therapy (CRT) Survey I dataset-a large multi-centre cohort of patients undergoing CRT implantation.

Methods and results

The SEMMELWEIS-CRT score is a machine learning-based tool trained for predicting all-cause mortality in patients undergoing CRT implantation. This tool demonstrated impressive performance during internal validation but has not yet been validated externally. To this end, we applied it to the data of 1367 patients from the European CRT Survey I dataset. The SEMMELWEIS-CRT predicted 1-year mortality with an area under the receiver operating characteristic curve (AUC) of 0.729 (0.682-0.776), which concurred with the performance measured during internal validation [AUC: 0.768 (0.674-0.861), P = 0.466]. Moreover, the SEMMELWEIS-CRT score outperformed multiple conventional statistics-based risk scores, and we demonstrated that a higher predicted probability is not only associated with a higher risk of death [odds ratio (OR): 1.081 (1.061-1.101), P < 0.001] but also with an increased risk of hospitalizations for any cause [OR: 1.013 (1.002-1.025), P = 0.020] or for heart failure [OR: 1.033 (1.015-1.052), P < 0.001], a less than 5% improvement in left ventricular ejection fraction [OR: 1.033 (1.021-1.047), P < 0.001], and lack of improvement in New York Heart Association functional class compared with baseline [OR: 1.018 (1.006-1.029), P = 0.003].

Conclusion

In the European CRT Survey I dataset, the SEMMELWEIS-CRT score predicted 1-year all-cause mortality with good discriminatory power, which confirms the generalizability and demonstrates the potential clinical utility of this machine learning-based risk stratification tool.

Current use of implantable electrical devices in Sweden: data from the Swedish pacemaker and implantable cardioverter-defibrillator registry

AIMS

The National Swedish Pacemaker and Implantable Cardioverter-Defibrillator (ICD) Registry collects prospective data on all pacemaker and ICD implants in Sweden. We aimed to report the 2012 findings of the Registry concerning electrical devices implantation rates and changes over time, 1 year complications, long-term device longevity and patient survival.

METHODS AND RESULTS

Forty-four Swedish implanting centres continuously contribute implantation of pacemakers and ICDs to the Registry by direct data entry on a specific website. Clinical and technical information on 2012 first implants and postoperative complications were analysed and compared with previous years. Patient survival data were obtained from the Swedish population register database. In 2012, the mean pacemaker and ICD first implantation rates were 697 and 136 per million inhabitants, respectively. The number of cardiac resynchronization therapy (CRT) first implantations/million capita was 41 (CRT pacemakers) and 55 (CRT defibrillators), with only a slight increase in CRT-ICD rate compared with 2011. Most device implantations were performed in men. Complication rates for pacemaker and ICD procedures were 5.3 and 10.1% at 1 year, respectively. Device and lead longevity differed among manufacturers. Pacemaker patients were older at the time of first implant and had generally worse survival rate than ICD patients (63 vs. 82% after 5 years).

CONCLUSION

Pacemaker and ICD implantation rates seem to have reached a level phase in Sweden. Implantable cardioverter-defibrillator and CRT implantation rates are very low and do not reflect guideline indications. Gender differences in CRT and ICD implantations are pronounced. Device and patient survival rates are variable, and should be considered when deciding device type.

Defibrillation testing during implantable cardioverter-defibrillator implantation in Italian current practice: the Assessment of Long-term Induction clinical ValuE (ALIVE) project

BACKGROUND

Clinical practice with regard to defibrillation threshold (DFT) testing during implantable cardioverter-defibrillator (ICD) implantation varies considerably, even among experienced implanting centers. International guidelines do not as yet mandate DFT testing.

OBJECTIVE

The objective of this project is to assess current clinical decision making regarding DFT testing during ICD implantation.

METHODS

The ALIVE project collected data on DFT testing from a multicenter network of Italian clinicians sharing a common system for the collection, management, analysis, and reporting of clinical and diagnostic data from patients with Medtronic (Minneapolis, MN) implantable devices.

RESULTS

Data on 2,082 consecutive patients implanted with a Medtronic ICD in 111 Italian centers, over the period 2007 to 2010, were analyzed. Defibrillation threshold testing was performed in 33% of cases (678/2,082). The main reasons for performing the test were physician's clinical practice ("I always perform DFT") (80%) and secondary prevention implantation (12%). The main reasons for not performing DFT testing were centers' practice (44%), primary prevention (31%), and device replacement (15%). In 22 patients, ventricular fibrillation induction was not achieved; 656 patients completed DFT testing: 633 patients (96%) performed a single test, 19 patients (3%) performed a second induction test, and 4 patients (0.6%) underwent an additional induction test.

CONCLUSIONS

The preliminary results of the ALIVE project show that a great number of implant procedures are performed without DFT testing in the common practice of the participating centers. We also measured an inhomogeneous, center-dependent DFT testing behavior, which suggests the importance of defining a common guideline for ICD implant testing. Follow-up data on our patients will provide more information on the clinical value of the test.

[Current clinical practise of cardiac resynchronisation therapy in Austria--national results from the European CRT Survey]

Cardiac resynchronization therapy (CRT) has become an established treatment modality in patients with chronic heart failure, reducing both mortality and morbidity. However, patient selection, implantation and follow-up require great clinical experience. Between 2008 and 2010, the European Society of Cardiology initiated the European CRT survey to describe the current practice and routines associated with CRT implantations in 13 countries. Data from 156 patients collected in 10 Austrian centres were analysed compared to the total 2438 patients enrolled. The survey data showed that general practice did not adhere to the present guidelines. More than one third (36%) of the patients had atrial fibrillation and more than one-fourth (29%) had had a device implanted previously. Altogether, 22% of the patients were in NYHA functional class I or II, and 18% had a LVEF > 35%. Approximately one-fourth of the patients were treated with CRT-P devices (Austria 23%, total 27%). In Austria a higher percentage of patients with non-ischemic cardiomyopathy was selected for CRT than in the other European countries (56% versus 40%, p < 0.0001). Less than a quarter of all patients were females. Different from the rest of Europe, only a minority of CRT implantations were performed by cardiologists in Austria (29% as compared to 89% throughout Europe; p < 0.0001).

[Progress in cardiac pacing]

This review discusses the utility and current status of remote monitoring in patients with cardiac devices in Spain, the different anticoagulation strategies used during device implantation, the surgical replacement and maintenance of pacemakers and defibrillators, and the present and future importance of impedance sensors in cardiac pacing and heart failure management. Finally, there is a summary of the most relevant scientific articles published in the last year.

Implementation of device therapy (cardiac resynchronization therapy and implantable cardioverter defibrillator) for patients with heart failure in Europe: changes from 2004 to 2008

AIMS

Heart failure (HF) patients increasingly receive device therapy, either an implantable cardioverter defibrillator (ICD) or a biventricular pacemaker, also called cardiac resynchronization therapy (CRT), or a CRT device with an ICD (CRT-D). However, epidemiological data on the use of device therapy in Europe are limited.

METHODS AND RESULTS

Data on implantation rates for conventional pacemakers, ICD, CRT, and CRT-D in 15 Western European countries were obtained from the Eucomed Registry for the 5-year period 2004-2008. Implantation of conventional pacemakers increased by 9% in Europe over the 5 years (reaching 907/million in 2008) and there were significant differences between countries. Implantable cardioverter defibrillator implantations increased by 75% from 80/million in 2004 to 140/million in 2008, and differences between countries were larger than those for conventional pacemakers. Implantation rates for CRT-P alone increased slightly from 2004 to 2006, but remained at 25/million thereafter in Europe overall. The total number of CRT implants (CRT-P and -D) markedly increased from 46/million in 2004 to 99/million in 2008 (115%), but this was mainly due to more CRT-D implants, i.e. an increase in the proportion of CRT-D (from 55% in 2004 to 75% in 2008). Implantation rates for ICD, CRT, and CRT-D remained markedly different throughout the study period between countries.

CONCLUSION

Implantation rates of devices for HF, in particular ICD and CRT-D, have increased significantly between 2004 and 2008 in Europe, but there remain major differences between countries.