Cath Lab Digest - November 2007 - (Page 38)

REVIEW NOVEMBER details of the clinical background are sketchy apart from the information related to the ACS. Given that we all have started treating patients > 85 years of age with PCI, and their risk of heart failure is often high because of their high cardiovascular risk (e.g., a diabetic smoker with hypertension and hyperlipidemia), I often wonder if it would be best to adopt a policy of PCI in these and other patients only if the procedure presents a small risk of compromising LV function. Medical treatment might often be a better option than “gung-ho” PCI. Incomplete knowledge of the background comorbidities in such circumstances makes me uncomfortable when deciding whether to proceed with PCI in such patients. PCI in poor LV systolic function. In those with already compromised LV systolic function, our PCI approach should include consideration of intra-aortic balloon pump (IABP) support. This is, without a doubt, the appropriate strategy for post-MI cardiogenic shock patients, as evidenced by the results of the SHOCK trial.16,17 In those without shock but with LVEF ≤ 30%, elective IABP might also be a wise choice before starting the PCI procedure to minimize the 20% risk of vascular instability in this group of patients and to ensure an uncomplicated and successful outcome.18 This strategy has been ratified in the ACC/AHA guidelines on PCI.19 The mechanism of benefit appears to be that IABP counterpulsation helps to maintain cardiac output by reduction of the afterload (with consequent reduction of oxygen consumption and myocardial ischemia) and may augment coronary perfusion.20,21 Distal protection and thrombectomy. Should we consider distal embolic protection to limit damage to LV function? Although distal embolic protection was not seen to be beneficial in patients undergoing primary PCI in the EMERALD (Enhanced Myocardial Efficacy and Recovery by Aspiration of Liberated Debris) study,22 there is good evidence for their benefit in PCI of saphenous vein grafts23 and in those with angioscopically proven plaque rupture causing acute STEMI.24 The latter two would certainly be strong indications to use distal protection for the microvasculature. There is increasing evidence that thrombectomy prior to stent implantation in pri- mary PCI might be helpful in improving myocardial perfusion by protecting the microvasculature, thereby limiting LV systolic dysfunction.25,26 PCI procedure is an opportunity to assess LV function. Our other responsibility is to ensure that all patients undergoing a PCI procedure have their LV function assessed and documented. This does not refer merely to those hospitalized with an ACS, as required by the United Kingdom MINAP (Myocardial Infarction National Audit Project) database,27 but all patients undergoing PCI, since this is our big chance to pick up those with asymptomatic LV dysfunction and start treatment with an ACE-inhibitor to prevent progression to overt heart failure. This is also our opportunity to start treatment to prevent heart failure for patients with high cardiovascular risk (as those undergoing PCI would be) and normal LV function. There is good evidence that in patients with high cardiovascular risk (those with diabetes, hypertension, hyperlipidemia and previous cardiovascular disease), early intervention with ACE inhibitors, angiotensin receptor-blockers, statins or antiplatelet therapy with clopidogrel significantly reduces the occurrence of heart failure, even when LV systolic function is normal.28–32 To be fair, assessment of LV function does take place during left heart catheterization in most cases, but I have a reason to emphasize this point. I have often been guilty myself of omitting the LV angiogram during the cardiac catheterization merely to cut short the procedure time (in my enthusiasm to proceed to launch into the PCI, particularly in ACS and primary PCI cases), with the instruction to perform an echocardiogram later on, which didn’t actually happen in that admission. That brings me to another point: the timing of LV function assessment following a MI. Early assessment of LV function in ACS. There is a need to assess LV function early after ACS if the full therapeutic benefit of the new aldosterone antagonist eplerenone is to be obtained. The EPHESUS trial involved 642 patients who were randomized 3 to 14 days after AMI if they had signs and symptoms of heart failure and an LVEF ≤ 40% to eplerenone or placebo in addition to optimal medical treatment. A significant reduction in overall mortality, death from cardiovascular (CVS) causes or hospitalization from CVS causes was seen in the eplerenone group at a mean follow up of 16 months. 33 Much of the benefits occurred early. At 30 days after randomization, 34 eplerenone reduced the risk of all-cause mortality by 31% (3.2% vs. 4.6% in eplerenoneand placebo-treated patients, respectively; p = 0.004), and reduced the risk of CV mortality/CV hospitalization by 13% (8.6% vs. 9.9% in eplerenone- and placebotreated patients, respectively; p = 0.074). Eplerenone also reduced the risk of CV mortality by 32% (p = 0.003), and the risk of sudden cardiac death by 37% (p = 0.051). In order to commence eplerenone early after MI, all such patients must undergo an early assessment of LV function, preferably by echocardiography. Reduce door-to-balloon time. There is enough evidence now to call for a 24-hour/7 days per week primary PCI program wherever possible in order to improve outcomes and reduce LV dysfunction in STEMI patients.8 The other important call is for the process of primary PCI to be facilitated with a view to reducing the time from symptom-onset to PCI.35 This means that we need to strive for better organization to reduce transfer times and minimize delays in primary PCI36 to ensure even less LV dysfunction and mortality. Based on current evidence, delayed PCI in untreated STEMI patients should be driven by symptoms rather than be a routine strategy.10,11 Rationale for preserving LV function during PCI at all costs. Why should we worry about causing a bit of LV dysfunction during PCIs which are often vital procedures to the patient? Because these things add up and add to what might be already there. And there is no denying that LV function is the major driver and predictor of outcomes in coronary artery disease,37–39 and also because of the heart failure epidemic that is threatening many of our patients. Let me refresh your memory with the statistics again. In the United Kingdom population, 3–20 per 1000 are currently suffering from heart failure.40 The number increases to more than 80 per 1000 people who are > 75 years of age. Year-on-year, the number of heart failure patients is on the rise, with at least 1 new case per 1000, and an annual increase in new patients of 10%.40 My aim is not to harp on the issue of side branch loss from PCI, but to focus the spotlight on what we could all do to prevent heart failure. My proposal. I propose that for all primary PCIs, rescue PCIs, percutaneous intervention for NSTEMI, as well as elective complex PCIs (including those where an apparently simple PCI has become complicated by side branch loss, dissection, no-reflow, etc.), an echocardiogram should be performed to document LV function immediately prior to the procedure and again at 6 months following the procedure. Significant LV dilatation of > 20% in end-diastolic volume or a reduction of ejection fraction should indicate the need for vigorous treatment with heart failure drugs such as ACEinhibitors, angiotensin receptorblockers, beta-blockers and, if required, spironolactone. LV enddiastolic pressure (LVEDP) should be recorded and LV angiography should also remain part of the diagnostic coronary angiographic study whenever possible, since these provide useful information on LV function. Troponin measurements post-PCI, in my view, do not add much to the assessment of remodeling following acute ischemic syndromes, and need not be routinely performed. ■ The authors can be contacted at banerjeep@aol.com References 1. Cohn JN, Ferrari R, Sharpe N. Cardiac remodeling — Concepts and clinical implications: A consensus paper from an international forum on cardiac remodeling. On behalf of an International Forum on Cardiac J Am Coll Cardiol Remodeling. 2000;35:569–582. 2. Frigerio M, Roubina E. Drugs for left ventricular remodeling in heart failure. Am J Cardiol 2005;96:10–18. 3. Bolognese L, Neskovic A, Parodi G, et al. Left ventricular remodeling following primary coronary angioplasty: Patterns of left ventricular dilation and long term prognostic implications. Circulation 2002; 106: 2351–2357. 4. Mannaerts HFJ, Van der Heide JA, Kamp O, et al. Early identification of left ventricular remodelling after myocardial infarction, assessed by transthoracic 3D echocardiography. Eur Heart J 2004; 25:680–687. 5. Balachandran KP, Berry C, Pell AC, et al. Improvement in left ventricular function following successful rescue percutaneous coronary intervention is independent of time-toJ Invasive Cardiol reperfusion. 2006;18:330–333. 6. Keeley EC, Boura JA, Grines CL. Primary angioplasty versus intravenous thrombolytic therapy for acute myocardial infarction: A quantitative review of 23 randomised trials. Lancet 2003;361: 13–20. 7 Fath-Ordoubadi F, Beatt KJ, Spyrou N, Camici PG. Efficacy of coronary angioplasty for the treatment of hibernating myocardium. Heart 1999;82;210–216. 8. Hochman JS, Lamas GA, Buller CE, et al.

Table of Contents Feed for the Digital Edition of Cath Lab Digest - November 2007

Henry Ford Heart and Vascular Institute Treating Patients with Complex Vascular Disease with a Multi-Disciplinary Approach Improving Patient Compliance with Antiplatelet Medications Clinical Editor’s Corner Cath Lab Nurse/Tech Vascular Access and Closure Using the StarClose® Device The Clinical and Economic Impact of Measuring Fractional Flow Reserve FFR and Choosing an Optimal Revascularization Strategy Finally! The New Registered Cardiac Electrophysiology Specialist (RCES) Credential Use of a Mobile Lab to ‘Test the Waters’ at a Rural Hospital Remembering a Cardiac Cath Lab History ACVP• Membership Page What Do You Think? The Ten-Minute Interview with… Ernie Livingston, RN, BSN SICP* Chapter Updates Who’s in Charge? Working to Eliminate Bottlenecks: Florida Hospital’s Cardiac Cath Lab Achieves Greater Efficiency and Higher Satisfaction Preserving Left Ventricular Function during Percutaneous Coronary Intervention Ask the Clinical Instructor: A Q&A Column for Those New to the Cath Lab Making the Most of Your First Impression: Interviewing Tips and Techniques CEU Education Center Clinical & Industry News Meetings Calendar

Cath Lab Digest - November 2007

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