Atrial fibrillation (AF) is the most common cardiac arrhythmia and often
occurs with heart failure (HF) [1]. AF prevalence increases with
increasing severity of HF: for instance its prevalence ranges from 5
percent in patients with New York Heart Association (NYHA) functional
class I HF to 40 percent in patients with NYHA class IV HF [2]. Its
presence with HF plays a significant prognostic role and increases
morbidity and mortality. Heart Failure with reduced ejection fraction
(HFrEF) is associated with cardiac arrhythmias [3]. HFrEF is also
one of the indications for Cardiac resynchronization therapy (CRT)
placement [4]. Therefore, many patients undergoing CRT implantation
will concomitantly have HF and AF. As the benefit from CRT in HF
patients has been established, the data on patients with both HF and AF
is limited, because patients with atrial arrhythmias were excluded from
most of the major CRT trials, such as CARE-HF and COMPANION [5].
However, a number of observational studies and small randomized clinical
trials suggest a benefit from CRT in AF and HF patients such as a
CRT-mediated ejection fraction (EF) increase [6, 7]. Other studies
showed a high non-response rate in patients with AF as compared to those
in sinus rhythm (SR) [8]. Thus, it is important to determine whether
CRT has a beneficial role in these patients to decide on adding an
atrial lead at the time of CRT implantation especially in patients with
longstanding-persistent AF.
In their published study, Ziegelhoeffer et al. investigated the outcomes
of CRT placement with an atrial lead in patients with HF and AF. This
was done by conducting a retrospective analysis of all patients with AF
who received CRT for HF at the Kerckhoff Heart Center since June 2004
and were observed until July 2018- completing a 5-year follow-up. The
authors identified 328 patients and divided them into 3 subgroups:
paroxysmal (px) AF, persistent (ps) AF, and longstanding-persistent (lp)
AF, with all patients receiving the same standard operative management.
During the observation period, the authors analyzed the rhythm course of
the patients, cardiac parameters (NYHA class, MR, LVEF, left atrial
diameter) and performed a subgroup analysis for patients who received an
atrial lead. The study showed that all groups had a high rate of sinus
rate (SR) conversion and rhythm maintenance at 1 and 5 years.
Specifically, the patients who received an atrial lead among the lp AF
group were shown to have a stable EF, less pronounced left ventricular
end-systolic diameter (LVESD) and left ventricular end diastolic
diameter (LVEDD) and lower mitral regurgitation (MR) rates at one year
follow-up as compared to the group without atrial lead placement.
Moreover, the results of the lp group were similar to the ps-AF group,
although the latter had a lower number of participants (n=4) without
initial implantation of the atrial lead. The authors attributed the
improvement in cardiac function and SR conversion to CRT and the
implantation of an additional atrial lead.
Although some studies showed that CRT therapy reduced secondary MR in HF
[9, 10], this study additionally suggests that CRT with an atrial
lead was associated with improved myocardial function and improvement of
interventricular conduction delay triggering cardiac remodeling in
patients with HF and AF. Although the results showed better cardiac
function in the subgroup analysis of the patients with an additional
atrial lead, these results were reported as percentages with no level of
significance specified, hence statistical significance of the difference
in the described parameters (such as LVESD, LVEDD) could not be
determined. Further investigation via prospective studies is needed with
larger sample size in the future to further support the results of the
study especially that it was done in a single center and had a
relatively small sample size.
References:
1. Chung MK, Refaat M, Shen WK, et al. Atrial Fibrillation: JACC Council
Perspectives. J Am Coll Cardiol. Apr 2020; 75 (14): 1689-1713.
2. Maisel, W.H. and L.W. Stevenson, Atrial fibrillation in heart
failure: epidemiology, pathophysiology, and rationale for therapy. Am J
Cardiol, 2003. 91 (6a): p. 2d-8d.
3. AlJaroudi WA, Refaat MM, Habib RH, et al. Effect of Angiotensin
Converting Enzyme Inhibitors and Receptor Blockers on Appropriate
Implantable Cardiac Defibrillator Shock: Insights from the GRADE
Multicenter Registry. Am J Cardiol Apr 2015; 115 (7): 115(7):924-31.
4. Yancy, C.W., et al., 2013 ACCF/AHA guideline for the management
of heart failure: a report of the American College of Cardiology
Foundation/American Heart Association Task Force on Practice
Guidelines. J Am Coll Cardiol, 2013. 62 (16): p. e147-239.
5. Cleland, J.G., et al., The effect of cardiac resynchronization
on morbidity and mortality in heart failure. N Engl J Med, 2005.352 (15): p. 1539-49.
6. Leclercq, C., et al., Comparative effects of permanent
biventricular and right-univentricular pacing in heart failure patients
with chronic atrial fibrillation. Eur Heart J, 2002. 23 (22):
p. 1780-7.
7. Upadhyay, G.A., et al., Cardiac resynchronization in patients
with atrial fibrillation: a meta-analysis of prospective cohort
studies. J Am Coll Cardiol, 2008. 52 (15): p. 1239-46.
8. Wilton, S.B., et al., Outcomes of cardiac resynchronization
therapy in patients with versus those without atrial fibrillation: a
systematic review and meta-analysis. Heart Rhythm, 2011. 8 (7):
p. 1088-94.
9. van Bommel, R.J., et al., Cardiac resynchronization therapy as
a therapeutic option in patients with moderate-severe functional mitral
regurgitation and high operative risk. Circulation, 2011.124 (8): p. 912-9.
10. Breithardt, O.A., et al., Acute effects of cardiac
resynchronization therapy on functional mitral regurgitation in advanced
systolic heart failure. J Am Coll Cardiol, 2003. 41 (5): p.
765-70.