When to Refer Heart Failure for ICD, CRT, LVAD or Transplant

A heart failure patient should be referred for device therapy when symptoms persist despite optimal medical therapy and the ECG and echocardiogram meet clear criteria: an ejection fraction of 35% or less for an implantable cardioverter-defibrillator (ICD), and, in addition, sinus rhythm with left bundle branch block and a broad QRS for cardiac resynchronisation therapy (CRT). Patients who remain refractory are assessed for a left ventricular assist device (LVAD) or a heart transplant.

Dr. Rajpal Singh R L, Director Cardiology, Fortis Hospitals, Bannerghatta Road, Bangalore, India, devoted the final part of his teaching to this question: when should a physician who has done everything possible at their own end refer a heart failure patient, and what can a specialist centre then offer? He is an experienced device therapist; as a consultant in the UK he built up the CRT service at the Wolverhampton Heart and Lung Centre. This article covers the ECG-based referral triggers, how ICDs and CRT work, the four criteria for CRT that any physician can check, mitral and surgical options, LVADs, transplant and the role of palliative care. The complete guide to heart failure detection and management gives the overall pathway, and the four pillars article covers the drug therapy that must be optimised first.

Why advanced heart failure needs more than drugs

Advanced heart failure needs more than drugs because medication alone does not always prevent sudden cardiac death or halt pump failure. Patients with heart failure face two separate threats: progressive pump failure and sudden cardiac death from ventricular arrhythmias. Drugs address both, but not always enough. Dr. Singh's message was that physicians should not stop at medication in a patient with advanced heart failure. They should think about how to improve both quality of life and longevity, and for longevity the devices that make the difference are ICDs and CRT. For patients who are not suitable for those devices, LVADs and heart transplantation have excellent outcomes in selected cases.

When to refer for an ICD or CRT: the ECG and ejection fraction

The ECG and the ejection fraction decide when to refer: an ejection fraction of 35% or less on optimal therapy triggers ICD referral, and a broad QRS with left bundle branch block adds CRT. For stable heart failure patients, Dr. Singh asks physicians to repeat an ECG and an NT-proBNP every six to twelve months. The ECG shows whether the QRS complex (the part of the trace that records the ventricles contracting) is broadening or a bundle branch block is developing as fibrosis progresses, and together with the ejection fraction it sorts patients into three groups:

Patients with heart failure and an ejection fraction of 35% or less are at high risk of sudden cardiac death, which is why they should be considered for an ICD once their drug therapy is optimal. Under ESC guidelines, the ejection fraction is reassessed after about three months of optimised therapy before the decision is made, since some patients improve enough not to need a device.

How an implantable defibrillator (ICD) works

An ICD is a device implanted under the skin with a lead in the right ventricle. It monitors the heart rhythm continuously and treats dangerous ventricular arrhythmias. Patients with ischaemic cardiomyopathy, meaning heart failure caused by coronary artery disease, are at particularly high risk of sudden cardiac death because scarred myocardium generates ventricular tachycardia.

Dr. Singh explained the device's tiered response:

1. Anti-tachycardia pacing. When fast ventricular tachycardia starts, the device first paces the heart rapidly to interrupt it. In his experience this works in about 90% of patients, without a shock.
2. Watchful monitoring of slower rhythms. Slow ventricular tachycardia is programmed to be monitored for longer, because most episodes settle on their own; if one does not, the device applies anti-tachycardia pacing.
3. A shock. If pacing fails and the rhythm accelerates, the device delivers a shock.

Cardiac resynchronisation therapy (CRT)

CRT is a pacemaker with three leads that makes the walls of the left ventricle contract together again. In many heart failure patients, electrical conduction is delayed so that the septum and the lateral wall of the left ventricle contract out of sequence. This dyssynchrony, visible on echocardiography, wastes much of each heartbeat.

CRT corrects it with three leads:

• an atrial lead in the right atrium
• a right ventricular lead
• a left ventricular lead passed through the coronary sinus into a lateral cardiac vein on the outside of the left ventricle

The device stimulates the lateral wall first so that the two walls contract together, and it also improves coordination between the right and left ventricles. Lead position is critical. Dr. Singh's team performs a venogram of the coronary sinus to find a good posterolateral cardiac vein, because placing the lead in an anterior or posterior vein makes no difference to function.

What CRT achieves

CRT improves the ejection fraction by several percentage points in most responders, and by considerably more in so-called super-responders. It reduces the functional mitral regurgitation caused by a dilated ventricle, reduces pulmonary congestion and improves quality of life. On the summary of numbers needed to treat that he showed, CRT in correctly selected patients had one of the lowest figures of any heart failure therapy, in single digits.

CRT criteria: four questions for the general physician

Dr. Singh reduced CRT selection to four questions any physician can answer from the clinical picture and an ECG:

1. Is the patient still symptomatic, with an ejection fraction of 35% or less, despite optimal medical therapy?
2. Does the ECG show left bundle branch block, with a QRS width of more than 130 milliseconds?
3. Is the patient in sinus rhythm?
4. Does the patient have a life expectancy of more than one year?

If the answer to all four is yes, the patient is an ideal candidate for CRT. ESC guidelines give the strongest recommendation when the QRS is 150 milliseconds or more, with a weaker recommendation between 130 and 149 milliseconds.

CRT-P vs CRT-D

CRT comes in two forms:

• CRT-P: a resynchronisation pacemaker alone, for heart failure therapy.
• CRT-D: a resynchronisation pacemaker combined with a defibrillator, which adds protection against sudden death.

Dr. Singh's practice is to use CRT-D in patients with coronary artery disease, who carry the higher arrhythmic risk of ischaemic cardiomyopathy, and CRT-P in patients with dilated cardiomyopathy. Both work effectively.

Complete heart block with a weak ventricle

One error Dr. Singh specifically warned against: a patient with complete heart block and left ventricular dysfunction should not receive a conventional dual-chamber pacemaker. Constant pacing from the right ventricle alone can worsen dyssynchrony. These patients should have a left ventricular lead in a lateral cardiac vein, which makes the device a CRT system. Physiological pacing of the heart's own conduction system is an emerging alternative but is still at an early stage; CRT remains the proven therapy.

Bypass surgery and mitral procedures for symptomatic patients

When optimal medical therapy is in place and the patient is still symptomatic, other structural options may help:

• Surgical revascularisation. In ischaemic cardiomyopathy, bypass surgery can be considered, although at higher risk; the cost of coronary artery bypass grafting is listed separately.
• Secondary mitral regurgitation. When the left ventricle is so stretched that the mitral leaflets no longer meet, the regurgitation can be addressed by CRT, by a transcatheter mitral clip (edge-to-edge repair), or by a coronary sinus-based procedure that shrinks the mitral annulus.

Dr. Singh's advice was not to hesitate in referring such patients to a dedicated heart failure specialist.

LVAD for advanced heart failure: how it works, cost and stay

An LVAD is a mechanical pump that does the work of the failing left ventricle. An inflow tube is placed in the apex of the left ventricle; blood passes through a high-energy pump, and the outflow is connected to the aorta. The pump sits in the chest, and a driveline exits through the skin to a controller and batteries that the patient wears, allowing them to walk around and live at home.

At Fortis Bannerghatta Road, LVADs are implanted by Dr. Singh's surgical colleagues, while he admits, optimises and stabilises patients before surgery. The team performs a few LVADs a year.

Cost and stay. Dr. Singh put the cost of an LVAD at about 80 lakh rupees. He acknowledged that the cost implication is large, and stressed that the treatment works very effectively. Patients travelling from Africa need to stay at least two to three months.

A patient's experience. One of his patients, a man from Central Africa, received an LVAD after a stay in India of several months covering optimisation, surgery and recovery. He returned home, has now lived with the device for four years, and came back recently for routine battery replacement, doing well. Dr. Singh noted that he had recently spoken with another patient with advanced heart failure who was planning to travel for the same treatment.

Dr. Biswarup Purkayastha's article on LVADs as a bridge to transplant or destination therapy covers candidacy and device options in more depth.

Heart transplant for advanced heart failure

Heart transplantation is also available at Fortis Bannerghatta Road, and in selected patients with advanced heart failure it has excellent outcomes. Patients with refractory heart failure in Dr. Singh's heart failure clinic undergo advanced imaging, including cardiac MRI, and biopsy where needed, followed by formal assessment for an LVAD or a transplant. For international patients, the separate guide to heart transplant in India for foreign nationals explains the eligibility and allocation process.

Palliative care is a legitimate choice

Not every patient will go on to a device, an LVAD or a transplant. When a patient has reached the end of the road, because of the disease or because of finances, Dr. Singh's view is that it is not wrong to discuss palliative care: to plan a comfortable life with fewer medicines and fewer admissions, rather than continuing treatment that no longer helps.

Working with a specialist before referral

Dr. Singh invited referring physicians to contact him for an opinion on any cardiology patient, whether the question is heart failure, coronary disease or TAVI, even if only to check that their management is on track. In most cases, he said, a response comes within 12 to 24 hours, provided all the data are shared. The cost of ICD implantation at partner hospitals is set out on the AICD implantation cost page, and the questions doctors raised during the session are covered in the Live Discussion. Related material is in the cardiology specialty hub.