About one hundred European cardiologists discussed the role of calcium antagonists in the follow-up management of myocardial infarction, β-blockers are the treatment of choice. Where these are contra-indicated or otherwise unsuitable, many clinicians would use a non-dihydropyridine calcium antagonist alone or in combination with an ACE inhibitor. There is broad agreement that calcium antagonists should not be used in patients with concomitant left ventricular failure. Cholesterol estimation in post-infarction patients is essentia

Ferrari, R.

Hansen, J. Fischer

Lüscher, T. F.

Opie, L. H.

RERO DOC Digital Library

European Heart Journal (1997) 18 {Supplement A), A134-A138How European cardiologists perceive the role ofcalcium antagonists in follow-up after myocardialinfarctionL. H. Opie, T. F. Luscher*, R. Ferrarif and J. Fischer Hansen±Heart Research Unit and Hypertension Clinic, Department of Medicine, University of Cape Town, Cape Town,South Africa; *University Hospital, Zurich, Switzerland; 'f Chair of Cardiology, University of Brescia, Brescia,IRCCS, Salvatore Maugeri Foundation, Gussago, Brescia, Italy; %Department of Cardiology, Hvidowe Hospital,University of Copenhagen, DenmarkAbout one hundred European cardiologists discussed therole of calcium antagonists in the follow-up management ofmyocardial infarction. /?-blockers are the treatment ofchoice. Where these are contra-indicated or otherwise un-suitable, many clinicians would use a non-dihydropyridinecalcium antagonist alone or in combination with an ACEinhibitor. There is broad agreement that calcium antagon-ists should not be used in patients with concomitant leftventricular failure. Cholesterol estimation in post-infarctionpatients is essential.(Eur Heart J 1997; 18 (Suppl A): A134-A138)Key Words: Calcium antagonists, myocardial infarction,beta-blockers, left ventricular failure, ACE inhibitors,cholesterol.IntroductionAcute myocardial infarction is a spectrum of eventsranging from the early phase, soon after the onset ofchest pain, through to the late post-infarction phase.There have been few studies of calcium antagonists inthe acute phase so there is little evidence that they are ofbenefit. It is therefore not surprising that only 8% of theparticipants in the interactive groups were interestedin using these agents in the acute early phase of myo-cardial infarction; 43%, however, would consider usinga calcium antagonist after the patient had left thecoronary care unit and was in a general ward, or had lefthospital and was being followed-up by a physician orcardiologist.Choice of agentWhen it came to the choice of calcium antagonists, thevast majority of participants would use one of the non-dihydropyridines. Only 5% would use a dihydropyridinein a patient who had had a myocardial infarction.Professor Opie suggested that dihydropyridines might beuseful on occasion even though no trial data existed tosupport their use. The only study (SPRINT1121) hadCorrespondence: Prof. Roberto Ferrari, Chair of Cardiology,University of Brescia, Spedali Civili, P.le Spedali Civili, 1, 25123Brescia, Italy.shown no advantage for secondary prevention but thenifedipine used in the study had been the short-actingform which clinicians would not consider using today.One concern participants expressed about thelong-acting dihydropyridines was that the existingdata suggest that they fail to reduce the plasmacatecholamine level and may even increase it.Beta-blockadeNinety percent of the participants thought that beta-blockade should be used in patients who had had amyocardial infarction. European cardiologists haveclearly been impressed by the weight of evidence thatbeta-blockade has a protective effect.Twenty to 30% of patients have contra-indications to beta-blockers yet, of those who could takethe drug, only 50% actually receive it. Clinicians mayhesitate to use beta-blockers because patients, particu-larly elderly ones, complain of tiredness, depression,sleeping problems and reduced capacity for exercise. It istherefore important to look at other methods of second-ary prophylaxis. In Denmark, verapamil has become adrug of first choice'41.ACE inhibitorsWhen beta-blockade was contra-indicated, in patientswith respiratory problems or diabetes, for instance,O195-668X/97/0A0134+O5 SI8.00/0 •f 1997 The European Society of Cardiology1Calcium antagonists in myocardial infarction A135about 50% of participants would use a non-dihydropyridine calcium antagonist and 31% a combi-nation of a non-dihydropyridine calcium antagonist andan ACE inhibitor.This was an interesting response because there isno real evidence that ACE inhibitors work as secondaryprophylaxis in patients without heart failure thoughthere are some signs that they might. They may havelong-term effects by endothelial protection, and perhapsby the production of bradykinin, but they should not beconsidered as first choice for secondary prevention.For those who choose a non-dihydropyridine,the evidence of effectiveness is strongest for verapamilthough both verapamil and diltiazem are contra-indicated in heart failure.In deciding between a calcium antagonist aloneor in combination with an ACE inhibitor, the actualevidence favours the calcium antagonist but indirectdata favour the combination. One attraction of thecombination is that the drugs interact with differentmechanisms and the clinician may be able to use a lowerdose of each drug. In the end the decision is a matter ofjudgement. There are no hard data defining the 'right'way to manage these patients.Secondary preventionIn the later post-MI stages, when the question ofsecondary prevention arises, the choice of treatmentdepends on whether the patient shows evidence of heartfailure. For patients who were not in heart failure, theinteractive groups agreed that the choice of drug toachieve secondary prophylaxis lay between a beta-blocker and a non-dihydropyridine calcium antagonist.The choice could be based on the expected toleranceand side-effects of a particular drug, or the doctor'sfamiliarity with its use.Patients with heart failureIt was less easy to achieve agreement about the treat-ment of patients with left ventricular failure though thevast majority of participants agreed that, on presentevidence, calcium antagonists should not be used.Faced with a patient with angina and left ven-tricular systolic dysfunction (ejection fraction <30%),31% of participants would use an ACE inhibitor and45% an ACE inhibitor in combination with beta-blockade. The reasoning behind this choice was thatthough the ACE inhibitor would have no direct effect onthe angina, it could act indirectly. It would allow the leftventricle to maintain an optimal size and shape, reduceoxygen demand and decrease sympathetic release duringexercise. It was also suggested that there was reasonable,if not perfect evidence that beta-blockade can be used inthese circumstances.Thirty-five percent of participants thought beta-blockade was contra-indicated because of evidence ofdeleterious effects on patients with systolic dysfunctionand overt heart failure. They pointed out that beta-blockade is still an investigative treatment in thesepatients. This opinion is shared by the American Collegeof Cardiology which has recently issued a statement thatthe use of beta-blockade in congestive heart failure isstill under evaluation.The majority of participants felt, however, thatthere probably was a case for using beta-blockade in thepost-infarction stage, though not as sole therapy. Theywere impressed by the evidence that beta-blockade incarefully given built-up doses may benefit left ventricularfailure.In the discussion, Professor Liischer pointed outthat the patient had a poor prognosis so there was aneed not just to treat his symptoms but also to improvehis prognosis. ACE inhibitors would do this. For helpwith his angina, the only option Liischer would considerwas beta-blockade, which might also improve the prog-nosis. The data in support of beta-blockade were not assolid in patients with an ejection fraction below 30%as they were for those with values above that level.Professor Liischer would, however, favour treating thispatient with a combination of ACE inhibitor and beta-blocker.Dr Fischer Hansen said there was no real evi-dence to support the choices the participants had made.In his unit they would use an ACE inhibitor'3' andlong-acting nitrates. If that was not effective they mightconsider using verapamil or a beta-blocker, though hehesitates to give these drugs in patients with poorventricular function because of the lack of evidence thatthey offer any benefit to the patient.Diabetes and dyslipidaemiaThe case reports included patients who were diabetic,or had a high level of circulating lipids. In those circum-stances most of the participants preferred verapamil to a/?-blocker, particularly because there is some evidencethat verapamil can assist blood glucose control. There isno such evidence for beta-blockers. These drugs mayeven worsen blood glucose control.After discussion, all participants agreed thatestimation of the blood cholesterol level was an essentialinvestigation in the post-infarction period, and that evenin patients with only a moderate degree of lipid elev-ation, there should be a vigorous attack on cholesterollevels.This consensus decision reflects the way in whichthe attitude to cholesterol in secondary prevention hasundergone a radical revision. The controversy is clearlyover. The evidence now available suggests that inpatients with signs of atherosclerosis who have had aninfarction, the estimation of cholesterol is mandatory.The level of cholesterol that determines interventionshould be set quite low.Diet and weight control should be used butthis group of patients who require not primary butEur Heart J, Vol. 18, Suppl A 1997A136 L. H. Opie et al.Secondary prophylaxisLVEF35 40 80ACE-InhibitorsBeta-BlockersVerapamilAspirinFigure 1 Drug therapy in post-MI patients classifiedusing left ventricular ejection fraction. Adapted fromJ. Fischer HansenFigure 2 Drug therapy in post-patients classified due toclinical findings of CHF in the acute phase of MI.Adapted from J. Fischer Hansensecondary prevention, need early intervention with drugtherapy.Possible protocolsWhen classifying patients who have had a myocardialinfarction, it is possible to do so in a way that helpsdetermine the type of secondary prevention that shouldbe used. One way of classification (Fig. 1) is to useechocardiography. A left ventricular ejection fractionbelow 35% is a clear indication for secondary preventionwith an ACE inhibitor.There is less certain information about treatmentwith /?-blockers or with verapamil. The data availablesuggest that verapamil should be used only in patientswith normal or slightly depressed systolic function./?-blockers may be used over a wider range.Another method of classification is to considerclinical findings during the acute stage of infarction, aswas done in the AIRE study'31 and DAVIT II[4]. Patientswere then divided into those with and without clinicalfindings of congestive heart failure (Fig. 2). The AIREstudy demonstrated that if patients had had congestiveheart failure while in the coronary care unit, theyFigure 3 Drug therapy in post-MI patients classified dueto CHF and therapy with diuretics in the CCU. Adaptedfrom J. Fischer Hansenbenefited from an ACE inhibitor. DAVIT II showedthat verapamil benefited those without heart failure orslightly depressed systolic function.A third way of classification (Fig. 3) is based onwhether the patients had heart failure in the coronarycare unit and whether they were still receiving diuretics.Dr Fischer Hansen suggested that a simple, practicalapproach to the management of patients in the post-infarction stage is to ask: 'Does this patient need adiuretic?' If the answer is 'yes', he or she should be givenan ACE inhibitor. If the answer is 'no', secondaryprevention should be provided with an anti-ischaemicdrug. Dr Fischer Hansen favours verapamil, but abeta-blocker could also be used.All patients need cholesterol control. All of themshould also receive aspirin except those who have atrialfibrillation in which case coumarin offers better protec-tion. Low blood flow in a large atrium may encouragefibrin-dependent thrombus formation. Trials in atrialfibrillation suggest that coumarin is superior to aspirinfor this particular indication.The authors would like to acknowledge the assistance of DrMichael O'Donnell and Paul Castle in the preparation of themanuscript.References[1] The Israeli SPRINT study group. Secondary prevention rein-farction Israeli nifedipine trial (SPRINT I). A randomizedintervention trial of nifedipine in patients with acutemyocardial infarction. Eur Heart J 1988; 9: 354-64.[2] Goldbourt U, Behar S, Reicher-Reiss H et al. Early admin-istration of nifedipine in suspected acute myocardial infarction.The Secondary prevention reinfarction Israeli nifedipine trial 2study. Arch Intern Med 1993; 153: 345-53.[3] The Acute Infarction Ramipril Efficacy (AIRE) study investi-gators. Effect of ramipril on mortality and morbidity of sur-vivors of acute myocardial infarction with clinical evidence ofheart failure. Lancet 1993; 342: 821-8.[4] The Danish study group on verapamil in myocardial infarction.Effect of verapamil on mortality and major events after acutemyocardial infarction (The Danish Verapamil Infarction TrialII-DAVIT II). Am J Cardiol 1990; 66: 779-85.Eur Heart J, Vol. 18, Suppl A 1997Calcium antagonists in myocardial infarction A137Case 1Male, 76 yearsPresent history:Patient admitted directly to CCU with chestdiscomfort, sweating, chills, and generalmalaise of sudden onset beginning 1 hr beforeadmissionPrevious history:Systemic hypertension for 20 yearsRare episodes of chest discomfort with exerciseEpisodes of podagra/goutCigarettes 5/day for 60 yearsTreatment before admission:Metoprolol: 50 mg/dayHydrochlorothiazide:Amiloride:Prazosine:50 mg/day5 mg/day5 mg/dayStatus:No dyspnoeaNo signs of congestive heart failureBlood pressure: 180/120 mmHgHeart rate: 48 bpmAcute treatment:APSAC, heparine, aspirin, morphine,oxygenUncomplicated causeWhat should you know or examine ?100Exercise testLoad Heart rateRest50 Watt100 Watt125 Watt5895118129Rate pressure product:RestMaximalMaximal/Rest =8700309603.5Systolic BP150190240240EchocardiogramLeft ventricle:Which treatment would you administerat discharge ?100Diameter in diastole:Diameter in systole:Posterior wall thickness:Septum thickness:Wall motion index:Left atrial diameter:44 mm33 mm20 mm16 mm1.7 (EF = 50%)48 mm806040200_77%27%10%Aspirin Beta- Nifedipine Diltiazem Verapamil DiureticsblockerEur Heart J, Vol. 18, Suppl A 1997A138 L. H. Opie et al.Regarding AMI, in which phase of AMIdo you think calcium antagonists couldbe used ?10080 -604020100-13%8% ^ _• 3% •27%•1 1%_—J5%43%I•I•85§8IS|J '111g | | .fsfI HiShould beta-blockade be used post-MI ?Yes SometimesDo you think there are differences betweencalcium antagonists in relation topost-MI use ?80604020• H 98%•I•1%Yes No SometimesIf beta-blockade is contraindicated(respiratory problems, diabetes),which drug(s) would you use ?Which drugs are contraindicated in thepresence of systolic heart failure andclinical symptoms ?100Beta- ApE- Verapamil None of theblocker inhibitor aboveIn post-MI patients with LV systolicdysfunction (i.e. depressed LV ejectionfraction <30%) and angina, whichof the following drugs is indicated ?10080 -604020-—_1%31%•HT_o45%••4%19%•a o C OJp.2-DS =s<C P31*=Eur Heart J, Vol. 18, Suppl A 1997

How European cardiologists perceive the role of calcium antagonists in follow-up after myocardial infarction

Abstract

Similar works

Full text

Available Versions

RERO DOC Digital Library