View source for PCI in the patient with severely depressed ventricular function

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{{PCI}}
{{CMG}}; '''Associate Editor-In-Chief''': Vijayalakshmi Kunadian MBBS, MD, MRCP

==Overview==
[[Heart failure]] (HF) is a major public health problem. In the United States, 5 million patients have [[heart failure]] and annually more than one million are hospitalized with [[heart failure]]. In addition 50,000 patients die of [[heart failure]] in the United States. [[CAD|Coronary artery disease (CAD)]] is the most common cause of [[heart failure]] as a result of [[left ventricular systolic dysfunction]] (60-68%). There are no [[randomized control trial|randomized studies]] to evaluate the best strategy to manage [[coronary artery disease]] in this patient population. However, there are a number of registry studies that evaluated percutaneous coronary intervention (PCI) and [[CABG|coronary artery bypass surgery (CABG)]] in patients with [[CAD|coronary artery disease]] and [[heart failure]].
==Mechanism of Functional Recovery after Revascularization==
Patients with [[heart failure|HF]] can have hibernating or [[myocardial stunning|stunned myocardium]]. Hibernating [[myocardium]] in [[chronic]]ally [[dysfunctional]] tissue related to inadequate [[myocardial]] blood flow<ref name="pmid2783527">{{cite journal| author=Rahimtoola SH| title=The hibernating myocardium. | journal=Am Heart J | year= 1989 | volume= 117 | issue= 1 | pages= 211-21 | pmid=2783527 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2783527  }} </ref>. [[myocardial stunning|Stunned myocardium]] refers to [[dysfunction]] in viable [[myocardium]] related to transient [[ischemia]]<ref name="pmid12766493">{{cite journal| author=Kim SJ, Depre C, Vatner SF| title=Novel mechanisms mediating stunned myocardium. | journal=Heart Fail Rev | year= 2003 | volume= 8 | issue= 2 | pages= 143-53 | pmid=12766493 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12766493  }} </ref>. Previous studies have demonstrated that both hibernating [[myocardium]] and [[myocardial stunning|stunned myocardium]] can lead to [[left ventricular systolic dysfunction]], [[ventricular remodeling|remodeling]] and eventually development of [[heart failure]]. Chareonthaitawee et al demonstrated that 60% of ischemic [[LV dysfunction]] is related to [[dysfunctional]] but viable [[myocardium]]<ref name="pmid16098417">{{cite journal| author=Chareonthaitawee P, Gersh BJ, Araoz PA, Gibbons RJ| title=Revascularization in severe left ventricular dysfunction: the role of viability testing. | journal=J Am Coll Cardiol | year= 2005 | volume= 46 | issue= 4 | pages= 567-74 | pmid=16098417 | doi=10.1016/j.jacc.2005.03.072 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16098417  }} </ref>. [[myocardial stunning|Stunned]] and hibernating [[myocardium]] could potentially be improved by [[revascularization]] by optimizing [[perfusion]] into the [[myocardium]].
[[Image:PCI HF.JPG|thumb|500px|left| Management algorithm for patients with [[LV dysfunction]] and suspected [[CAD]] –Image adapted from Phillips et al. AHJ. 2007;153:S65-73]]

==Role of PCI==
The benefit of PCI in patients with [[heart failure]] related to [[myocardial stunning|stunned myocardium]] has been studied in [[observational studies]]. Keelan et al subdivided patients undergoing PCI in [[heart failure|HF]] into 3 categories: group 1, [[ejection fraction|ejection fraction (EF)]] ≤40%; group 2, [[ejection fraction|EF]] 41% to 49%; and group 3, [[ejection fraction|EF]] ≥50%. The respective [[mortality]] rates were 11.0%, 4.5%, and 1.9% (p <0.001) after 1 year. The composite end points of death/ [[myocardial infarction]] ([[MI]]) and death/ [[MI]]/ [[CABG]] occurred more frequently among patients in group 1. Thus, significant [[LV dysfunction]] was still associated with increased in-hospital and 1-year [[mortality]] in patients having contemporary PCI<ref name="pmid12745097">{{cite journal| author=Keelan PC, Johnston JM, Koru-Sengul T, Detre KM, Williams DO, Slater J et al.| title=Comparison of in-hospital and one-year outcomes in patients with left ventricular ejection fractions <or=40%, 41% to 49%, and >or=50% having percutaneous coronary revascularization. | journal=Am J Cardiol | year= 2003 | volume= 91 | issue= 10 | pages= 1168-72 | pmid=12745097 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12745097  }} </ref>.

The [[GRACE|GRACE (Global Registry of Acute Coronary Events) Registry]] demonstrated that the 6-month [[mortality]] was significantly lower in the PCI treated group compared to the medical [[therapy]] group (14% vs. 23.7%, p=<0.0001)<ref name="pmid14744970">{{cite journal| author=Steg PG, Dabbous OH, Feldman LJ, Cohen-Solal A, Aumont MC, López-Sendón J et al.| title=Determinants and prognostic impact of heart failure complicating acute coronary syndromes: observations from the Global Registry of Acute Coronary Events (GRACE). | journal=Circulation | year= 2004 | volume= 109 | issue= 4 | pages= 494-9 | pmid=14744970 | doi=10.1161/01.CIR.0000109691.16944.DA | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14744970  }} </ref>. PCI in [[chronic total occlusion]] in the setting of [[heart failure|HF]] has been shown to be beneficial. [[Stent]]ing can be safely performed in patients with [[heart failure|HF]] with acceptable late [[adverse event]]s.
 
A previous study demonstrated that patients with [[left ventricular ejection fraction|left ventricular ejection fraction (LVEF)]] ≤40% had better survival at 5 years if they received a [[stent]] compared with balloon angioplasty alone (76% for stents vs. 53% for balloon angioplasty; p<0.05). [[Stent]]ing was found to be significant predictor of late survival in patients with an [[left ventricular ejection fraction|LVEF]] ≤50% and [[left ventricular ejection fraction|LVEF]] ≤40%. This study demonstrates improved 5-year survival for patients undergoing [[stent]]ing compared with balloon angioplasty in patients with [[left ventricular ejection fraction|LVEF]] ≤40%<ref name="pmid16216018">{{cite journal| author=Lipinski MJ, Martin RE, Cowley MJ, Goudreau E, Malloy WN, Vetrovec GW| title=Improved survival for stenting vs. balloon angioplasty for the treatment of coronary artery disease in patients with ischemic left ventricular dysfunction. | journal=Catheter Cardiovasc Interv | year= 2005 | volume= 66 | issue= 4 | pages= 547-53 | pmid=16216018 | doi=10.1002/ccd.20455 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16216018  }} </ref>.

A recent study compared PCI using [[DES|drug eluting stents (DES)]] and [[CABG]]. The 2 years major [[adverse event|adverse]] [[cardiac]] and [[cerebrovascular]] [[adverse event|events]] free survival rate was 76% in [[DES]] group and 79% in the [[CABG]] [[cohort]] (p=NS)<ref name="pmid17585381">{{cite journal| author=Gioia G, Matthai W, Gillin K, Dralle J, Benassi A, Gioia MF et al.| title=Revascularization in severe left ventricular dysfunction: outcome comparison of drug-eluting stent implantation versus coronary artery by-pass grafting. | journal=Catheter Cardiovasc Interv | year= 2007 | volume= 70 | issue= 1 | pages= 26-33 | pmid=17585381 | doi=10.1002/ccd.21072 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17585381  }} </ref>. The same group demonstrated that [[DES]] reduced [[mortality]] and MACE compared to [[bare metal stent]]s. MACE rate was 10% for the [[DES]] group and 41% for the [[bare metal stent|BMS]] group (P = 0.003)<ref name="pmid16892436">{{cite journal| author=Gioia G, Matthai W, Benassi A, Rana H, Levite HA, Ewing LG| title=Improved survival with drug-eluting stent implantation in comparison with bare metal stent in patients with severe left ventricular dysfunction. | journal=Catheter Cardiovasc Interv | year= 2006 | volume= 68 | issue= 3 | pages= 392-8 | pmid=16892436 | doi=10.1002/ccd.20833 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16892436  }} </ref>.

==Surgical Revascularization==
The State University of New York study suggested that patients with [[heart failure|HF]] who underwent PCI had better outcomes than patients who underwent medical [[therapy]]. Over the last decade management of patients with significant [[heart failure]] has improved significantly. Better medical management strategies using [[statin]]s, [[ACEI|angiotensin converting enzyme inhibitors]] and the use of [[implantable defibrillators]] and [[cardiac resynchronization therapy]] have significantly improved the outcome of patients with [[heart failure]. PCI has also seen significant advance in recent years with availability of [[drug eluting stent]]s, [[IABP|intra-aortic balloon pump]] support and the use of low [[osmolar]] non-ionic [[contrast media]] which reduces the [[incidence]] of [[renal failure]] in patients with [[heart failure]]. Hence large [[randomized control trial|randomized clinical studies]] in the modern era are required to determine the best [[revascularization]] strategy for patients with [[heart failure]]<ref name="pmid15917382">{{cite journal| author=Hannan EL, Racz MJ, Walford G, Jones RH, Ryan TJ, Bennett E et al.| title=Long-term outcomes of coronary-artery bypass grafting versus stent implantation. | journal=N Engl J Med | year= 2005 | volume= 352 | issue= 21 | pages= 2174-83 | pmid=15917382 | doi=10.1056/NEJMoa040316 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15917382  }} </ref>. There are currently three [[randomized control trial|randomized trials]] are underway to evaluate the effect of [[revascularization]] in patients with [[ischemic]] [[dysfunction]] (STICH trial, [[HEART]] trial and PARR-2 trial<ref name="pmid15678031">{{cite journal| author=Doenst T, Velazquez EJ, Beyersdorf F, Michler R, Menicanti L, Di Donato M et al.| title=To STICH or not to STICH: we know the answer, but do we understand the question? | journal=J Thorac Cardiovasc Surg | year= 2005 | volume= 129 | issue= 2 | pages= 246-9 | pmid=15678031 | doi=10.1016/j.jtcvs.2004.07.060 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15678031  }} </ref><ref name="pmid14662282">{{cite journal| author=Beanlands R, Nichol G, Ruddy TD, deKemp RA, Hendry P, Humen D et al.| title=Evaluation of outcome and cost-effectiveness using an FDG PET-guided approach to management of patients with coronary disease and severe left ventricular dysfunction (PARR-2): rationale, design, and methods. | journal=Control Clin Trials | year= 2003 | volume= 24 | issue= 6 | pages= 776-94 | pmid=14662282 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14662282  }} </ref>).

==The Role of Viability Testing==
Viability studies could be beneficial in identifying patients who will benefit from [[revascularization]]. Viability can be assessed by [[single photon emission computed tomography|single photon emission computed tomography (SPECT)]], [[positron emission tomography|positron emission tomography (PET)]], [[dobutamine stress echocardiography]] and [[cardiac magnetic resonance imaging|cardiac magnetic resonance imaging (CMR)]]. Among patients who demonstrated viability the 1-year [[mortality]] was 16% in patients who underwent medical [[therapy]] and 3.2% in those who underwent [[revascularization]]. There was no difference in [[mortality]] in those who did not demonstrate viability. [[cardiac magnetic resonance imaging|CMR]] is now emerging as a gold standard for viability testing, but further studies are required to compare [[cardiac magnetic resonance imaging|CMR]] viability to clinical outcomes.

==Patient Selection for PCI== 
PCI and [[CABG]] should be considered as complimentary rather than competitive treatment for patients with [[heart failure]]. PCI could be considered in patients with focal [[stenosis]], patients who have had prior [[CABG]], with concomitant [[comorbidity|co-morbidities]] and advanced age. [[CABG]] should be considered in patients with [[diffuse]] disease pattern, complex [[lesion]]s including [[chronic total occlusion]]s and patients who require concomitant [[mitral valve surgery]]<ref name="pmid17394905">{{cite journal| author=Phillips HR, O'Connor CM, Rogers J| title=Revascularization for heart failure. | journal=Am Heart J | year= 2007 | volume= 153 | issue= 4 Suppl | pages= 65-73 | pmid=17394905 | doi=10.1016/j.ahj.2007.01.026 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17394905  }} </ref>.

==References==
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