To the Editor: In their review of primary percutaneous coronaryintervention (PCI) for myocardial infarction with ST-segmentelevation, Keeley and Hillis (Jan. 4 issue)1 cite the guidelinesof the American College of Cardiology and American Heart Association(ACC–AHA): "Primary PCI is preferred if a . . .catheterization laboratory with surgical backup [is] availableand if the procedure can be performed within 90 minutes afterinitial medical contact. . . ."2 Nationally,for 55% of patients who have myocardial infarction with ST-segmentelevation, the door-to-balloon time is less than 90 minutes.3Between January 2006 and July 2006, the hospital with the highestpercentage of patients with myocardial infarction with ST-segmentelevation meeting this criterion was a rural hospital that didnot have surgical backup: 100% of the patients had door-to-balloontimes of less than 90 minutes, and the average time was 55 minutes.Among these patients, there was no increase in complications.
Some rural areas have sufficient population to support a programin interventional cardiology but not a program in cardiac surgery.In rural communities, traffic congestion is rarely a problem,so that an interventional team could get to the hospital quickly.Primary PCI can be performed safely with superior results inrural settings without surgical backup.4 The ACC–AHA guidelinesmight compromise the care provided to patients with myocardialinfarction with ST-segment elevation who live in rural communities.
Daniel C. Brown, M.D. St. Luke's Magic Valley Regional Medical Center Twin Falls, ID 83301 dcbrown{at}mvrmc.org
References
Keeley EC, Hillis LD. Primary PCI for myocardial infarction with ST-segment elevation. N Engl J Med 2007;356:47-54. [Free Full Text]
Antman EM, Anbe DT, Armstrong PW, et al. ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction -- executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1999 Guidelines for the Management of Patients with Acute Myocardial Infarction). J Am Coll Cardiol 2004;44:671-719. [Erratum, J Am Coll Cardiol 2005;45:1376.] [Free Full Text]
Brown DC, Mogelson S, Harris R, Kemp D, Massey M. Percutaneous coronary interventions in a rural hospital without surgical backup: report of one year of experience. Clin Cardiol 2006;29:337-340. [Web of Science][Medline]
To the Editor: In their article on primary PCI for patientswho have myocardial infarction with ST-segment elevation, Keeleyand Hillis describe the management of this potentially fatalcoronary event, including medical treatment and mechanical therapywith primary PCI. However, some additional points should beaddressed. The authors state that clopidogrel should be administeredafter it has been determined that emergency bypass surgery isnot required. Recent study data indicate that the administrationof clopidogrel before PCI significantly reduces the incidenceof death from cardiovascular causes or from ischemic complicationswithout a significant increase in bleeding.1,2 Furthermore,the addition of the selective aldosterone blocker eplerenoneto optimal medical therapy has been shown to reduce morbidityand mortality among patients with acute myocardial infarctioncomplicated by left ventricular dysfunction and heart failureand thus should have been mentioned in this article.3 Finally,because of possible adverse effects on the clinical outcome,the risk of thrombocytopenia induced by treatment with heparinor glycoprotein IIb/IIIa inhibitors should also be noted.
Sebastian Szabo, M.D. Thomas Oikonomopoulos, M.D. Hans MartinHoffmeister, M.D. Städtisches Klinikum Solingen 42653 Solingen, Germany krisztinaszb{at}aol.com
References
Sabatine MS, Cannon CP, Gibson CM, et al. Effect of clopidogrel pretreatment before percutaneous coronary intervention in patients with ST-elevation myocardial infarction treated with fibrinolytics: the PCI-CLARITY study. JAMA 2005;294:1224-1232. [Free Full Text]
Chen ZM, Jiang LX, Chen YP, et al. Addition of clopidogrel to aspirin in 45,852 patients with acute myocardial infarction: randomised placebo-controlled trial. Lancet 2005;366:1607-1621. [CrossRef][Web of Science][Medline]
Pitt B, Remme W, Zannad F, et al. Eplerenone, a selective aldosterone blocker, in patients with left ventricular dysfunction after myocardial infarction. N Engl J Med 2003;348:1309-1321. [Erratum, N Engl J Med 2003;348:2271.] [Free Full Text]
To the Editor: Keeley and Hillis ignore atheroembolic renovasculardisease as a cause of nephropathy in patients who have undergonePCI. Atheroembolic disease accounts for approximately 5 to 10%of cases of acute renal failure1 and is an increasingly commoncause of renal insufficiency in the elderly. A review of 372autopsies identified cholesterol emboli in 2.4% of renal-tissuesamples. Inciting events, including vascular surgery, arteriography,angioplasty, anticoagulation with heparin, and thrombolytictherapy, can be identified in 50% of cases of cholesterol embolization.Arteriographic procedures are the most common cause of cholesterolembolization.2 Showers of cholesterol emboli occur in about50% of PCIs when a guiding catheter is passed through the aorta.3,4Most of these showers are clinically silent. In approximately1% of high-risk patients, an acute cholesterol emboli syndromedevelops, which is manifested as acute renal failure, mesentericischemia, decreased microcirculation to the extremities, and,in some cases, embolic stroke.3 Since most cases of atheroembolickidney disease are triggered by angiography, radiocontrast-inducednephropathy is easily invoked as an alternative diagnosis.1
Polu KR, Wolf M. Needle in a haystack. N Engl J Med 2006;354:68-73. [Free Full Text]
Badr KF, Brenner BM. Vascular injury to the kidney. In: Kasper DL, Braunwald E, Fauci AS, et al., eds. Harrison's principles of internal medicine. 16th ed. New York: McGraw-Hill, 2005:1706-10.
McCullough PA. Interface between renal disease and cardiovascular disease. In: Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's heart disease: a textbook of cardiovascular medicine. 7th ed. Philadelphia: W.B. Saunders, 2003:2161-72.
Meyrier A. Cholesterol crystal embolism: diagnosis and treatment. Kidney Int 2006;69:1308-1312. [Web of Science][Medline]
The authors reply: We congratulate Brown et al.1 on their excellentoutcomes with the use of primary PCI at a rural hospital withoutsurgical backup, but we disagree that this procedure can beperformed consistently in this setting and under these circumstances"safely with superior results." The favorable results of primaryPCI reported in selected community hospitals that do not havesurgical backup, such as the data reported by Brown et al.,1may not be achieved reliably at other facilities. Although urgentcoronary-artery bypass grafting (CABG) is not commonly requiredfor patients undergoing primary PCI, it is, in fact, necessaryfor an occasional patient, and the need often cannot be predicted.When CABG is required, the resultant delay incurred by the transferof the patient to another facility can result in high morbidityand mortality.2 Primary PCI has been clearly shown to be safeand effective at high-volume centers with surgical backup, withsupporting data from 23 randomized, controlled trials.3 In contrast,only one randomized trial comparing primary PCI and fibrinolytictherapy at community hospitals without surgical backup has beenreported.4 As a result, according to the ACC–AHA guidelines,5primary PCI without surgical backup is a class IIb indication.
As noted above, an occasional patient undergoing primary PCIrequires urgent CABG. In such a patient, previous administrationof clopidogrel substantially increases the risk of perioperativebleeding. For this reason, clopidogrel should not be given inthe setting of primary PCI until it is clear that bypass surgeryis not required. In some patients undergoing PCI, thrombocytopeniamay develop after the administration of a combination of a plateletglycoprotein IIb/IIIa inhibitor and heparin; the risk is similaramong those undergoing primary PCI for myocardial infarctionwith ST-segment elevation and those undergoing elective PCI.Currently, administration of the selective aldosterone blockereplerenone is not considered a standard of care for patientswho have myocardial infarction with ST-segment elevation.
Although an occasional patient undergoing an arteriographicprocedure may have cholesterol embolization, most cholesterolemboli, as noted by Kashyap et al., are clinically silent. Onlyrarely do cholesterol emboli cause acute renal failure.
Ellen C. Keeley, M.D. University of Virginia School of Medicine Charlottesville, VA 22908
L. David Hillis, M.D. University of Texas Southwestern Medical Center Dallas, TX 75390
References
Brown DC, Mogelson S, Harris R, Kemp D, Massey M. Percutaneous coronary interventions in a rural hospital without surgical backup: report of one year of experience. Clin Cardiol 2006;29:337-340. [Web of Science][Medline]
Lotfi M, Mackie K, Dzavik V, Seidelin PH. Impact of delays to cardiac surgery after failed angioplasty and stenting. J Am Coll Cardiol 2004;43:337-342. [Free Full Text]
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. [CrossRef][Web of Science][Medline]
Aversano T, Aversano LT, Passamani E, et al. Thrombolytic therapy vs primary percutaneous coronary intervention for myocardial infarction in patients presenting to hospitals without on-site cardiac surgery: a randomized controlled trial. JAMA 2002;287:1943-1951. [Erratum, JAMA 2002;287:3212.] [Free Full Text]
Antman EM, Anbe DT, Armstrong PW, et al. ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction -- executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1999 Guidelines for the Management of Patients with Acute Myocardial Infarction). Circulation 2004;110:588-636. [Erratum, Circulation 2005;111:2013.] [Free Full Text]
Previous
