Download Cardiac Resynchronisation Therapy: The Optimal QRS Duration

Foreword
Cardiac Resynchronisation Therapy:
The Optimal QRS Duration Revisited
M
echanical dyssynchrony, ie nonsynchronous contraction of the wall segments of the left ventricle
(intraventricular) or between the left and right ventricles (interventricular), impairs systolic function and
ventricular filling, increases wall stress and worsens mitral regurgitation. It is most readily defined by the
presence of QRS widening and left bundle branch block (LBBB) configuration on the electrocardiogram. Biventricular
pacing by atrial-synchronised pacing of the right ventricle and left ventricle via the coronary sinus to the basal or
midventricular left ventricle region accomplishes reverse remodelling of the left ventricle, and this mode of therapy
is now recommended by both European and US guidelines. Still, however, the precise indications for implementation
of cardiac resynchronisation therapy (CRT) are not established.
The optimum QRS duration, in particular, is a matter of ongoing debate. LBBB and QRS >150 s, female gender and
non-ischaemic aetiology are established predictors of response. There was initial evidence that CRT may be beneficial
even in mildly symptomatic patients (NYHA I or II) and a QRS >120 ms, especially in presence of LBBB morphology.1–3
However, we know now that a QRS duration <120 ms (LESSER-EARTH trial),4 or even <130 ms (EchoCRT),5 may be
Table 1: Recommendations of Guidelines for Cardiac Resynchronisation Therapy 8–11
ACCF/AHA 2013 Guideline on Heart Failure
SR, LVEF ≤35 %, LBBB, QRS ≥150 ms, NYHA III/IV
SR, LVEF ≤35 %, LBBB, QRS ≥150 ms, NYHA II
SR, LVEF ≤35 %, LBBB, QRS 120–149 ms, NYHA II/III/IV
SR, LVEF ≤35 %, non-LBBB, QRS ≥150 ms, NYHA III/IV
SR, LVEF ≤35 %, non-LBBB, QRS 120–149 ms, NYHA III/IV
SR, LVEF ≤35 %, non-LBBB, QRS ≥150 ms, NYHA II
SR, LVEF ≤30 %, non-LBBB, QRS ≥150 ms, NYHA I
ESC 2015 Guideline on Ventricular Arrhythmias and SCD
I-A
I-B
IIa-B
IIa-A
IIb-B
IIb-B
IIb-C
ESC 2013 Guideline on Cardiac Pacing and CRT
Sinus rhythm
LVEF <35%, QRS
LVEF <35%, QRS
LVEF <35%, QRS
LVEF <35%, QRS
QRS <120 ms
>150 ms, LBBB, NYHA II-IV
120–150 ms, LBBB, NYHA II-IV
>150 ms, non-LBBB, NYHA II-IV
120–150 ms, LBBB, NYHA II-IV
I-A
I-B
IIa-B
IIb-B
III-B
Atrial fibrillation
LVEF ≤35%, QRS ≥120, NYHA III/IV
provided that a biventricular pacing as
close to 100 % as possible can be achieved.
CRT = cardiac resynchronisation therapy; SR = sinus rhythm;
LVEF = left ventricular ejection fraction; LBBB = left bundle branch block ;
NYHA = New York Heart Association; SCD = sudden cardiac death
80
AER Foreword 5.2 FINAL.indd 80
IIa-B
Sinus rhythm and NYHA III/ambulatory IV
LVEF
LVEF
LVEF
LVEF
≤35
≤35
≤35
≤35
%, LBBB, QRS >150 ms
I-A
%, LBBB, QRS 120–150 msI-B
%, no LBBB, QRS >150 msIIa-B
%, no LBBB, QRS 120–150 ms
IIb-B
Atrial fibrillation and NYHA III/ambulatory IV
LVEF ≤35 %, QRS >120–150 ms
and 100 % biventricular pacing achievable
I-B
Sinus rhythm with mild (NYHA II) heart failure
LVEF ≤30 %, LBBB, QRS >130 ms
LVEF ≤35%, QRS ≥150 ms
I-A
IIb-A
ESC 2016 Guideline on Heart Failure
CRT to reduce morbidity and mortality:
SR, LVEF ≤35%, LBBB,QRS ≥150 msI-A
SR, LVEF ≤35%, LBBB,QRS 130–149 msI-A
SR, LVEF ≤35%, non-LBBB,QRS ≥150 ms
IIa-B
SR, LVEF ≤35%, non- LBBB,QRS 130–149 ms
IIb-B
AF, LVEF ≤35%, NYHA III-IVa,QRS ≥130 ms
I-A
provided a strategy to ensure biventricular
capture is in place or the patient is expected
to return to sinus rhythm.
CRT is contraindicated in patients with
a QRS duration <130 ms
III-A
ARRHYTHMIA & ELECTROPHYSIOLOGY REVIEW
16/08/2016 21:39
Foreword
detrimental. In patients with mild heart failure, CRT defibrillators (CRT-D) may also be beneficial in non-LBBB patients
with PR interval prolongation and left ventricular ejection fraction (LVEF) <30 %, but with a QRS duration ≥130 ms.6
Patients with QRS >130 ms may also respond to CRT even if LVEF >30 %.7
These data are reflected in the recently published ESC guidelines on heart failure.8 In contrast to previous ESC
as well as US guidelines,9–11 a minimal QRS duration of 130 ms is now required for recommendation of CRT
(Table 1).8–11 Perhaps, this is a reasonable step towards a more rational use of our resources: CRT may be
beneficial in certain clinical settings, but as the BLOCK-HF trial has taught us, the potential of increased LV
lead-related complications should always be considered.12 CRT is a valuable therapeutic mode, but cautious
use is necessary to ensure its continuing efficiency in both medical and socio-economic terms.
Demosthenes Katritsis,
Editor-in-Chief, Arrhythmia & Electrophysiology Review
Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, US
1.
2.
3.
4.
5.
Goldenberg I, Kutyifa V, Klein HU, et al. Survival with
cardiac-resynchronisation therapy in mild heart failure.
N Engl J Med 2014;370:1694–701. DOI: 10.1056/
NEJMoa1401426; PMID: 24678999
Linde C, Abraham WT, Gold MR, et al. Randomized trial
of cardiac resynchronization in mildly symptomatic
heart failure patients and in asymptomatic patients with
left ventricular dysfunction and previous heart failure
symptoms. J Am Coll Cardiol 2008;52:1834–43. DOI: 10.1016/j.
jacc.2008.08.027; PMID: 19038680
Abraham WT, Young JB, León AR, et al. Effects of cardiac
resynchronization on disease progression in patients with
left ventricular systolic dysfunction, an indication for an
implantable cardioverter-defibrillator, and mildly symptomatic
chronic heart failure. Circulation 2004;110:2864–8. DOI:
10.1161/01.CIR.0000146336.92331.D1; PMID:15505095
Thibault B, Harel F, Ducharme A, et al. Cardiac
resynchronization therapy in patients with heart failure
and a QRS complex <120 milliseconds: the Evaluation
of Resynchronization Therapy for Heart Failure (LESSEREARTH) trial. Circulation 2013;127:873–81. DOI: 10.1161/
CIRCULATIONAHA.112.001239; PMID: 23388213
Steffel J, Robertson M, Singh JP, et al. The effect of QRS
duration on cardiac resynchronization therapy in patients
with a narrow QRS complex: a subgroup analysis of the
6.
7.
8.
9.
EchoCRT trial. Eur Heart J 2015;36:1983–9. DOI: 10.1093/
eurheartj/ehv242; PMID: 26009595
Kutyifa V, Stockburger M, Daubert JP, et al. PR interval
identifies clinical response in patients with non-left
bundle branch block: a Multicenter Automatic Defibrillator
Implantation Trial-Cardiac Resynchronization Therapy
substudy. Circ Arrhythm Electrophysiol 2014;7:645–51. DOI:
10.1161/CIRCEP.113.001299; PMID: 24963007
Kutyifa V, Kloppe A, Zareba W, et al. The influence of
left ventricular ejection fraction on the effectiveness of
cardiac resynchronization therapy MADIT-CRT (Multicenter
Automatic Defibrillator Implantation Trial With Cardiac
Resynchronization Therapy). J Am Coll Cardiol 2013;61:936–44.
DOI: 10.1016/j.jacc.2012.11.051; PMID: 23449428
Ponikowski P, Voors AA, Anker SD, et al. 2016 ESC Guidelines
for the diagnosis and treatment of acute and chronic heart
failure: The Task Force for the diagnosis and treatment of acute
and chronic heart failure of the European Society of Cardiology
(ESC)Developed with the special contribution of the Heart
Failure Association (HFA) of the ESC. Eur Heart J 2016;37:2129–
200. DOI: 10.1093/eurheartj/ehw128; PMID: 27206819
Yancy CW, Jessup M, Bozkurt B, et al. ACCF/AHA 2013
Guideline for the management of heart failure: a report of
the American College of Cardiology Foundation/American
Heart Association Task Force on Practice Guidelines.
10.
11.
12.
J Am Coll Cardiol 2013;62:e147–e239. DOI: 10.1016/j.
jacc.2013.05.019; PMID: 23747642
Brignole M, Auricchio A, Baron-Esquivias G, et al.
2013 ESC guidelines on cardiac pacing and cardiac
resynchronization therapy: the task force on cardiac pacing
and resynchronization therapy of the European Society
of Cardiology (ESC). Developed in collaboration with the
European Heart Rhythm Association (EHRA). Europace
2013;15:1070–118. DOI: 10.1093/europace/eut206; PMID:
23801827
Priori SG, Blomström-Lundqvist C, Mazzanti A, et al. 2015
ESC Guidelines for the management of patients with
ventricular arrhythmias and the prevention of sudden
cardiac death: The Task Force for the management of
patients with ventricular arrhythmias and the prevention of
sudden cardiac death of the European Society of Cardiology
(ESC) Endorsed by: Association for European Paediatric and
Congenital Cardiology (AEPC). Europace 2015;17:1601–87.
DOI: 10.1093/europace/euv319; PMID: 26318695
Curtis AB Worley SJ, Adamson PB, et al; Biventricular
versus Right Ventricular Pacing in Heart Failure Patients
with Atrioventricular Block (BLOCK HF) Trial Investigators.
Biventricular pacing for atrioventricular block and systolic
dysfunction. N Engl J Med 2013;368:1585–93. DOI: 10.1056/
NEJMoa1210356; PMID: 23614585
DOI: 10.15420/AER.2016.5.2.ED1
ARRHYTHMIA & ELECTROPHYSIOLOGY REVIEW
AER Foreword 5.2 FINAL.indd 81
81
16/08/2016 21:39