Introduction Cardiac resynchronisation therapy (CRT) is indicated in patients with left ventricular dysfunction (EF≤35%), electro-mechanical dyssynchrony, and limiting heart failure (HF) symptoms despite optimal medical therapy. In many cases target doses of HF medications prior to CRT are not achieved due to bradycardia and/or limiting hypotension. CRT however provides bradycardia backup and improved haemodynamics, thus providing an opportunity to further optimise HF medical therapies known to confer substantial morbidity and mortality benefits. We conducted the present study to evaluate the potential to further optimise medical treatments in patients receiving CRT within the framework of nurse-led pre and post CRT clinics.
Methods Our unit operates an integrated CRT service with pre-assessment, implantation, and follow-up components. Pre-assessment and follow-up incorporate dedicated HF nurse clinics to support protocol-driven optimisation of medical therapies. We therefore conducted a retrospective analysis of our CRT database over a 9-month period to quantify the frequency of use, and dose of HF medications (βblockers; βB, angiotensin converting enzyme inhibitors: ACE-I or angiotensin receptor blockers: ARB, aldosterone antagonists, digoxin, and loop diuretics) before and 6 months after CRT. Total daily dose equivalences within each class of medication (bisoprolol for βB, lisinopril for ACE-I/ARB, spironolactone for aldosterone antagonists, and frusemide for loop diuretics) and titration protocols were based on National Institute of Clinical Excellence guidelines for HF (guideline 5).
Results Between October 2009 and Jun 2010, 74 patients (age: 67±11 yrs, 86% male) underwent implantation of a CRT device. All patients attended the pre and post CRT nurse clinic to optimise medical therapies and provide adjunctive HF support. Abstract 75 table 1 describes the frequency of use and daily dose equivalent of each class of medication used in the patients prior to and 6 months after device implantation. The frequency of βB and digoxin use increased by 10% and 5% respectively. In addition, the dose of βB, ACE-I/ARB, and digoxin significantly increased, while the dose of loop diuretics significantly reduced in the 6 months after CRT implantation.
Conclusions The beneficial haemodynamic and pacing profiles provided by CRT offer important opportunities to further optimise heart failure medications after device implantation. In a dedicated nurse-led CRT follow-up clinic, we successfully initiated β blockers and digoxin in previously naive patients, and significantly uptitrated the doses of β blockers, ACE-I/ARB, and digoxin, while significantly reducing loop diuretic use in the 6 months after device implantation.
- cardiac resynchronisation therapy
- heart failure