March 27th, 2013
Left to Our Many Devices, Which One Do We Choose?
Mark Dayer, MD PhD FRCP and James Fang, MD
A 63-year-old male smoker with type 2 diabetes presents for the first time with chest pain and shortness of breath at rest. He has no recent history of viral infection and no family history of heart failure or sudden cardiac death.
Initial laboratory testing documents negative troponin, normal calcium, normal serum angiotensin-converting-enzyme (ACE) activity, and a negative HIV test. He has no hilar lymphadenopathy.
After being managed with intravenous diuretics and stabilized with ramipril 1.25 mg once daily and furosemide 40 mg twice daily, the patient still has significant limitations and mobilizes comfortably only around the bed. His systolic blood pressure (about 95 mm Hg) prevents the introduction of a beta-blocker. His intermittently high potassium level (up to 6.1 mmol/liter) precludes use of an aldosterone antagonist.
Electrocardiogram: left bundle-branch block, QRS duration 120 msec, and first-degree heart block (PR interval, 220 msec).
Echocardiogram: dilated left ventricle (end-diastolic diameter, 5.8 cm); LV ejection fraction, using Simpson’s biplane, of 16%; mildly dilated and significantly impaired right ventricle; elevated pulmonary artery pressure (about 50 mm Hg).
Coronary angiography: normal coronary arteries
MRI: no late gadolinium enhancement
Cardiac monitoring: periodic 2:1 heart block (<10% of the time)
All of the clinicians who considered the patient’s case agree that a device is warranted.
Which device should this patient receive as chronic therapy?
1. Dual-chamber pacemaker. The patient currently does not pace >40% of the time, and his expected progress is hard to determine. His device can be upgraded if he stabilizes in NYHA class III or better (although not according to current UK guidelines) and if optimal medication does not improve his left-ventricular function.
2. Cardiac resynchronization therapy–pacemaker (CRT-P) device. The patient’s ventricular function is poor and is unlikely to recover significantly. Furthermore, his conduction disease will progress, and he is likely to become dependent on pacing during the lifetime of the device. Given that he is arguably still in NYHA class IV, albeit ambulatory, he is currently not eligible for a defibrillator.
3. CRT–defibrillator (CRT-D) device. The patient is improving and with good medical therapy is likely to improve further. He has very poor ventricular function, and his conduction disease raises the possibility of a laminopathy, further increasing his risk level.
4. Another option
April 11, 2013
This patient has several worrisome clinical features, including advanced symptoms despite maximal tolerated therapy, the inability to titrate to target doses of heart-failure medications, pulmonary hypertension, and conduction-system disease. In light of these issues, it is not clear to me that he is “likely to improve further.” Ivabradine is not available in the U.S. but could be considered to augment his modest medical therapy without risking exacerbation of his atrioventricular (AV) block.
I do agree that device therapy is indicated (and guideline supported) in this situation; in fact, device therapy may enable initiation of beta-blockade, which the patient’s current AV block (but not his BP) does not permit. Notably, device therapy provides a “bridge” to advanced therapies, as the natural history of this patient is likely to be inexorable progression of heart failure. The worrisome 2:1 AV block with a baseline left bundle-branch block also requires dual-chamber pacing, preferably biventricular (e.g., with a cardiac resynchronization therapy–defibrillation device).
A Lyme titer should be checked if the patient’s history warrants it. There is little circumstantial evidence for sarcoid, despite the AV block. (Laminopathy, as noted, is a good thought as well and would be supported by a family history.)
April 18, 2013
We implanted a cardiac resynchronization therapy–pacemaker device with a high-voltage lead in the right ventricle. In the UK, the use of implanted cardioverter–defibrillators (ICDs) for a dilated cardiomyopathy is still much debated. NICE guidelines are expected to clarify the issue in 2014. We have referred the patient for genetic testing for a laminopathy and have tested him for Lyme serology (it is not something we usually overlook in the rural area where I practice).
When I examined the patient very recently, his clinical presentation was, perhaps surprisingly, much better. He walked up four flights of stairs to the cardiology clinic, although he was breathless at the top. He now takes ramipril 2.5 mg daily, and his blood pressure remains below 100 mm Hg. He is keen to go back to work (as a machine operator).
I will see him again in 2 months, when I will order a repeat echocardiogram to assess remodeling. He and I talked about the option of an upgrade to an ICD, but he is concerned about possible effects on his employment and about the (perhaps) increased risk for interactions between the ICD and the machines he operates at work.
We have a patient with newly diagnosed non-ischemic CMYP, who has a clear indication for pacing at 2:1 Heart Block will likely worsen with BBlocker therapy.
He has not been on optimal medical therapy and has class III-IV.
I would favour implanting a PACING DEVICE without an ICD component.
Use of CRT is little bit tricky here. LBBB with QRSD ~120 msec is a marginal indication at baseline but if does a significant amount of RV pacing , paced QRS is probably going to be significantly wider.
Since there is signifcant chance of progressively worse AV block on BB therapy (required therapy for CHF), I would be inclined to recommed a CRT-P device and consider upgrade to CRT-D in 6-12 months if his functional status improves and EF remains < 35%.
Good suggestion Sandeep- a concern of course being the fact that this gentleman would then be required to undergo another procedure in 6-12 months if he does need a defibrillator. I would suggest doing an EP study to see if he has inducible VT and if he does, then placing CRT-D
this patient has non ischemic cardiomyopathy. What would be the endpoint for an EP study? VT or VF? we can induce VF with no much trouble. The comment says VT. I dont think this was studied for non ischemic CM as it was for ischemic (MUSTT) but is an interesting option.
This patient with NIDCM, LBBB, and severe HF may be a really good candiate for CRT.
It may potentially even result in significant normalization of LV function.
Regarding, just PPM or ICD along with CRT, I don’t remember the last time we placed a CRT-P device. I am on an EP doctor and don’t know the stats behind this but maybe its a US vs. Europe thing.
In summary, I would go with the CRT-D without further studies.
Nice case for discussion. I agree. Might also test for DCM mutations, as a laminopathy would increase our confidence that a defibrillator is justified (as well as its potential value for relatives).
A case with loaded questions:
1. What is the risk for sudden cardiac death for a 63 y/o guy with non-ischemic, idiopathic, dilated cardiomyopathy, LBBB morphology with QRS duration 120 msec, NYHA class III, not on beta-blocker (hypotension and intermittent 2:1 AV block), or aldo blocker (hyperK) but no LGE on cardiac MRI?
– I think this patient’s SCD risk is high. Positive LGE on CMRI may adversely affect SCD risk. I’m not sure it’s absence necessarily decrease his SCD risk.
2. Is a defibrillator warranted for someone not on optimal medical therapy for primary prevention of SCD? (Particularly not being on a beta-blocker known to decrease risk of SCD and improve LV function in the long-term)
– My understanding is the gov’t won’t pay for one at least.
3. How much does the lack of gadolinium enhancement on CMRI predict the chance of reverse remodeling or affect the risk of SCD?
– There’s some data that lack of LGE on CMRI for non-ischemic CMP may have better chance with LV reverse remodeling and lower risk of SCD that those with + LGE. J Am Coll Cardiol. 2012;60(17):1659-1667. doi:10.1016/j.jacc.2012.05.054
If this were my patient, I would consider this alternative approach:
Implant a CRT-P, prescribe a wearable ICD (to treat me the provider, WCD has no strong data, result of VEST trial pending), add carvedilol and uptitrate as tolerated, wait 3 months and see what his ventricular function does and hope for the best.
I would like to introduce another option with the following background:
– I think likelyhood of complete remodeling to LVEF > 35 at 3 months is low.
– hospital and myself wont get compensated for ICD before at least 3 monhs of HF diagnosis (not the most important thing but still of consideration).
OPTION 4: implant CRT=P (BLOCK HF indication) using a HV lead (defib lead) in the RV. Wait 3-6 months. If EF remodels, no need for further intervention. If not, changeout pulse generator, it will be faster and less dangerous than extracting pacing lead and implanting a new defib later.
PRICE: he may end up with hardware that is not needed (one defib coil).
External wearable defibrillator: I will discuss with patient and leave it up to him. Not excited about it.
Thank you for all of your suggestions.
After some debate we settled on a CRT-P device. I used a high-voltage defib lead in the right ventricle, which will make an upgrade to an ICD more straightforward if required. I would anticipate that this will need to be discussed at some stage in the next year.
We have sent him for genetic testing to look for a laminopathy.
In the UK provision of ICDs for patients with dilated cardiomyopathy is still debated with variable provision across the country. Patients with dilated cardiomyopathy were excluded from the NICE guidance issued in 2006. New NICE guidance is anticipated in 2014.