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Atrial Fibrillation
Predicting thromboembolic risk in atrial fibrillation is a growth industry. The simplicity of the CHADS2 scoring system, which seemed too good to be true probably is: the lack of recognition of vascular disease and under estimation of the risk associated with age in particular producing falsely reassuring results. A Danish group have examined the predictive value of both CHADS2 and the more aggressive CHA2DS2vasc in a cohort of over 70 000 patients.
Headline findings are: the added risk factors in CHA2DS2vasc hold up well; those with a CHA2DS2vasc of 1 are at genuinely intermediate risk (2%pa) whereas CHADS2 of 1 have an uncomfortably high risk (4.75% pa). Risks are maintained year on year.
JB Oleson and others BMJ 2011;342:d124
We know that Dabigatran is more effective than warfarin (at high dose) and safer than warfarin (at reduced dose), but is it cost effective (stop yawning)? A group wanted to find if Dabi was cost effective, so, as is the way with these things, they did. The cost per QALY of high dose Dabigatran when compared with warfarin at current US prices was $50K.
The study has many limitations including a notional cost of warfarin, which seems very high and an assumption that observations in RE-LY over 2 years can be extrapolated in the long term.
JV Freeman and others Ann Intern Med. 2011;154:1-11
Heart Failure and Devices
Heart failure is an ever growing problem due to our ageing population, improved revascularisation techniques, and evidenced based secondary prevention. Cell therapy is hoping to be the next big thing in treating heart failure patients. Sadly, the results of the SEISMIC trial of intramyocardial implantation of autologous skeletal myoblasts, in a small cohort patients, were not earth moving. Whilst the technique appears safe and feasible, there was no benefit in LVEF, with ‘suggestions’ of improvement in symptoms. Further larger studies are awaited.
H Duckers and Others EuroIntervention. 2011;6:794-797
Better news for heart failure patients comes from the CHAMPION study, in which a wireless implant (CardioMEMS) that monitors haemodynamics has been shown to reduce hospitalisations compared to standard management. The pulmonary artery pressure sensor was implanted in NYHA class III patients, improving management and outcome over a 15 month follow up. I suspect this will appeal to device companies, implanters and patients, but feel that basic management and heart failure support in the community is needed first.
WT Abraham and Others. The Lancet;377:658-666.
Apparent primary prevention ICD candidates have been shown to lack benefit and even derive harm when implanted soon after an acute event (most studied in MI or CABG). It has become accepted, though not particularly illuminating, to describe this as ICDs
changing the mode of death in these populations.
A thorough examination of the DINAMIT data sheds some light. Essentially patients at high risk of early arrhythmias are also those at the highest risk of other modes of death (progressive heart failure, recurrent ischaemia, non cardiac morbidity).
P Dorian and others Circulation. 2010;122:2645-2652
Risk stratification for sudden death in Brugada syndrome has been controversial since the condition was described. An Italian registry of 320 patients provides a further contribution. Observations arising reinforce the role of a spontaneous type 1 ECG, syncope and male gender, but also resurrect family history and electrophysiological studies as relevant factors. In particular the negative predictive value of EPS when a rigorous and aggressive protocol is followed warrants further evaluation.
P Delise and others European Heart Journal (2011) 32, 169–176
It is well recognised that ischaemic patients derive less benefit than non ischaemics from CRT. It has always been assumed this is due to a higher burden of full thickness scar. This radionucleide study provides support for this with low scar burden ischaemics doing better post CRT than higher scar burden (regardless of dysynchrony measures).
Evan C. Adelstein and others, European Heart Journal (2011) 32, 93–103
After more than ten years one would have hoped we would have got past “two centre non randomised comparison” studies to tell us how to assess dysynchrony in narrow QRS heart failure patients. Sadly we have not, but the latest contribution (for what it is worth) suggest two echo measures: opposite wall delay (OWD) >75ms and anteroseptal posterior wall delay assessed by speckle tracking (ASPD) >107ms.The ROC curve for OWD is particularly unimpressive, but the ASPD cut off suggested gives sensitivity and specificity of 71 and 75% respectively for echocardiographic response to CRT. We look forward to validation of these results by other operators.
RJ Van Bommel and others European Heart Journal (2010) 31, 3054–3062
Should a tiered therapy zone be programmed in for primary prevention ICDs? Obviously, according to virtually every experienced implanter or physiologist I’ve met, and yes according to this piece from the PROVE trial. Basically, patients implanted with a device because they’re at risk of ventricular arrhythmias, get ventricular arrhythmias and would rather have them treated by ATP if possible than by shocks.
M Saeed and others J Cardiovasc Electrophysiol, Vol. 21, pp. 1349-135
Should we be optimising AV delay in all CRT implants? No because it doesn’t make any difference.
K Ellenbogen and others Circulation. 2010;122:2660-2668
Coronary Heart Disease
Another novel treatment with recent disappointing results is gene therapy for severe coronary artery disease. The NOVA trial, a small muliticentre randomised, double-blind, placebo (sham)-controlled study of direct intramyocardial injection of genes encoding vascular endothelial growth factor (VGEF), was again safe and feasible, but made no difference to exercise capacity or time to ischaemic threshold. Symptoms improved in both groups, similar to previous findings with transmyocardial revascularisation.
Kastrup and Others EuroIntervention. 2011;813-818
Another month, another risk score for cardiovascular patients. The ASSIGN CV risk score has been evaluated against the Framingham and QRISK scores in primary care patients in England and Wales and is as good/bad. All models overestimated risk, particularly for men with low specificity and sensitivity. Family history and ethnicity are important and QRISK2 may be better.
B De la Iglesia and Others. Heart 2011;97:491-499.
Does Eptibatide (the Glycoprotein IIbIIa inhibitor) given upstream improve outcomes in ACS patients. No, unless the patients are also pre-treated with early clopidogrel loading, but it does lead to more bleeding according to the EARLY-ACS study.
