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Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
Different response rates to cardiac resynchronization therapy (CRT) according to the applied definition
Jerzy Wiliński1, Danuta Czarnecka, Wiktoria Wojciechowska
1I Klinika Kardiologii i Nadciśnienia Tetniczego, Collegium Medicum Uniwersytetu Jagiellońskiego w Krakowie. putamen@interia.pl
Insights
Cardiac resynchronization therapy (CRT) significantly improved ejection fraction, 6-minute walk distance, and reduced heart failure symptoms in chronic heart failure patients. However, response rates vary based on definition, highlighting the need for standardized assessment.
Area of Science:
- Cardiology
- Medical Devices
Background:
- Cardiac resynchronization therapy (CRT) is established for improving outcomes in select chronic heart failure (CHF) patients.
- A significant proportion of patients do not achieve optimal benefits from CRT.
Purpose of the Study:
- To evaluate the clinical and echocardiographic outcomes of CRT in patients with chronic heart failure.
- To assess the response rate to CRT based on various definitions.
Main Methods:
- Sixty CHF patients (NYHA III-IV, LVEF ≤35%, QRS >130ms) received biventricular stimulation (BiV).
- Patients were assessed echocardiographically and clinically before and 3 months after CRT implantation.
Main Results:
- Significant improvements observed in ejection fraction (EF), 6-minute walk distance (6-MWT), and NYHA class.
- Left ventricular volumes (LVEDV, LVESV) decreased significantly post-CRT.
- High rates of improvement were noted for EF, LVESV reduction, NYHA class, and 6-MWT, with 78.3% experiencing no heart failure hospitalization.
Conclusions:
- CRT demonstrates significant efficacy in improving cardiac function and clinical status in CHF patients.
- The definition used significantly impacts the calculated CRT response rate.
Background:
Solid evidence shows that cardiac resynchronization therapy (CRT) improves prognosis, physical capacity and quality of life in selected groups of patients with chronic heart failure (CHF). Nonetheless, marked percentage of patients seem not to benefit from CRT.
Material And Methods:
Sixty consecutive patients (aged 66.3 +/- 8.7 years, 57 men - 95%, 3 women - 5%) with CHF (71.7% with ischaemic and 28,3% with non-ischaemic origin) of stable for > or = 3 months NYHA III or IV class despite optimized pharmacotherapy, with left ventricle end-diastolic diameter (LVEDd) > or = 55 mm, left ventricular ejection fraction (EF) < or = 35% and QRS > 130 ms were evaluated before and 3 months after CRT implementation (biventricular stimulation BiV) echocardiographically and clinically.
Results:
EF increased (21.7% vs 26,6%, p<0,0001), 6-minute walk distance (6-MWT) rose (298.0 m vs 373.1 m, p<0,0001), left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume (LVESV) decreased (244.3 ml vs 226,4 ml, p=0.0002; 192.8 ml vs 168,7 ml, p<0,0001 respectively). Mean NYHA class dropped from 3.1 to 2.2 (p<0.0001). Absolute increase in EF of > or = 4%, > or = 5%, > or = 6% was observed in 63.2%, 52.6%, and 35.7% respectively; relative increase of > or = 25% presented 21.1%, > or = 10% reduction of LVESV--59.7%, > or = 15% reduction of LVESV--43.8%, decrease in NYHA class--78.3%, > or = 10% reduction of 6-MWT--66.7%, no death and no hospitalization due to heart failure--78.3%.
Conclusions:
Response to CRT rate differs markedly according to the applied definition.
