Prognostic importance of early exercise testing in men with suspected unstable coronary artery disease

In 276 men with suspected unstable coronary artery disease i.e.recurring chest pain of new onset, increasing symptoms of anginalchest pain in formerly stable angina pectoris or suspected non-Q-waveinfarction, an exercise test was performed 2–7 days afteradmission. Coronary events i.e. cardiac death (N=4), Q-waveinfarction (N=11) and coronary artery bypass grafting (N=34),were registered during one year follow-up. The indication forbypass grafting was incapacitating angina pectoris despite medication,and suitable coronary anatomy. Stepwise multiple regressionanalysis showed that S–T segment depression and limitingchest pain were the most important prognostic parameters regardingcoronary events. In patients with S–T segment depression>0.1 mV or limiting chest pain (N=94) the occurrence of Q-wavemyocardial infarction or cardiac death was 10.6% (N=10) comparedto 2.8% (N=5) in patients without these criteria (N=182) (P<0.01).Coronary arterty bypass graft surgery was performed in 33% (N=31)of the group with S–T segment depression >0.1mV orlimiting chest pain but in only 1.7% (N=3) of the other patients(P<0.001). Thus, in patients with suspected unstable coronaryartery disease, whose symptoms and signs of ischaemia are stabilizedby medication, an exercise test can safely be performed aftera few days ambulation in the ward. The early exercise test providesimportant prognostic information regarding the risk for severecoronary events within the next year.     

Prognostic importance of early exercise testing in men with suspected unstable coronary artery disease

In 276 men with suspected unstable coronary artery disease i.e.recurring chest pain of new onset, increasing symptoms of anginalchest pain in formerly stable angina pectoris or suspected non-Q-waveinfarction, an exercise test was performed 2–7 days afteradmission. Coronary events i.e. cardiac death (N=4), Q-waveinfarction (N=11) and coronary artery bypass grafting (N=34),were registered during one year follow-up. The indication forbypass grafting was incapacitating angina pectoris despite medication,and suitable coronary anatomy. Stepwise multiple regressionanalysis showed that S–T segment depression and limitingchest pain were the most important prognostic parameters regardingcoronary events. In patients with S–T segment depression>0.1 mV or limiting chest pain (N=94) the occurrence of Q-wavemyocardial infarction or cardiac death was 10.6% (N=10) comparedto 2.8% (N=5) in patients without these criteria (N=182) (P<0.01).Coronary arterty bypass graft surgery was performed in 33% (N=31)of the group with S–T segment depression >0.1mV orlimiting chest pain but in only 1.7% (N=3) of the other patients(P<0.001). Thus, in patients with suspected unstable coronaryartery disease, whose symptoms and signs of ischaemia are stabilizedby medication, an exercise test can safely be performed aftera few days ambulation in the ward. The early exercise test providesimportant prognostic information regarding the risk for severecoronary events within the next year.     

Lipoprotein(a) as a risk predictor for cardiac mortality in patients with acute coronary syndromes

Aims Raised lipoprotein(a) concentrations are considered to be arisk factor for atherothrombotic diseases. We examined whetherbaseline concentrations were a risk factor for an adverse outcomein patients admitted with acute coronary syndromes. Methods and Results Five hundred and nineteen patients admitted with suspected acutecoronary syndromes were studied and followed prospectively fora median of 3 years. The prognostic significance of a baselinelipoprotein(a) concentration of 30mg.dl^–1or lower forsubsequent cardiac death was assessed in patients with myocardialinfarction (266) and unstable angina (197) and compared withother variables in regression models. In patients with myocardialinfarction, a baseline lipoprotein(a) concentration of 30mg.dl^–1wasassociated with a 62% increase in subsequent cardiac death comparedto the lower concentration group (29·8% vs 18·6%,Log rankP=0·04). In a multivariate regression model abaseline lipoprotein(a) concentration of 30mg.dl^–1retainedits significance as an independent predictor of cardiac death(P=0·037). In patients with unstable angina, baselineconcentrations of 7·9mg.dl^–1were found to be significantpredictors of cardiac death in univariate (P=0·021) andmultivariate (P=0·035) regression models. Conclusion Baseline lipoprotein(a) concentrations in patients admittedwith acute coronary syndromes are associated with an increasedrisk of cardiac death. For patients with myocardial infarctiona concentration of 30mg.dl^–1appears appropriate as a riskdiscriminator; for patients admitted with unstable angina, however,much lower concentrations of lipoprotein(a) appear to be prognosticallyimportant.     

Subjective symptoms and well-being differ in women and men after myocardial infarction

The frequency of subjective cardiac and psychological complaintsamong men and women a year after a confirmed diagnosis of myocardialinfarction (MI) were compared. Among 660 survivors, 595 patientscompleted mailed questionnaires at home one year after the MI.There were 421 men, mean age 67.1±10.7 years, and 174women, mean age 72.1±10.6 years. Controlling for the significantly higher mean age among thewomen, the latter more often had a previous history of anginapectoris, 54.6% (P0.05) versus 42.9%, and heart failure, 24.7%versus 13.5% (P0.01). Despite these facts, the women were significantlyless often referred to CCU, 82.2% versus 91.7% (P0.05). Oneyear after the MI, controlling for differences in age and co-morbidity,women reported significantly higher frequencies of psychologicaland psychosomatic complaints, including sleep disturbances.These differences may have clinical implications for diagnosisand treatment of women with coronary heart disease.     

Heart volume and cardiovascular mortality: A 16 year follow-up study of 1984 healthy middle-aged men

The possible association between heart size measured duringa cardiovascular screening examination and cardiovascular mortalitywas studied in 1984 healthy men aged 40–59 years. At the16-year follow-up 278 had died, 150 from cardiovascular diseases.Cardiovascular mortality was 2.2 times higher among the 122men with heart size 500 ml. m^–2 than among those withheart size < 500 ml .m^–2. This association was, however,exclusively confined to men with physical fitness below medianin whom the corresponding mortality ratio was 4.6 (95% confidenceinterval 2.5–8.4; P<0.001) after adjustment for age,smoking, cholesterol, blood pressure and heart rale. Heart sizemeasurements from routine chest X-rays is fast, easy, inexpensiveand appears to provide valuable, independent screening informationin healthy, middle-aged men.     

Left ventricular hypertrophy and myocardial ischaemia in hypertension: The THAMES Study

A multicentre epidemiological study to detect the prevalenceof myocardial ischaemia in hypertensive left ventricular hypertrophy(LVH) was performed in 188 asymptomatic male hypertensives (131treated). The mean age was 55 (range 40–82) years withblood pressure (BP) 160/100 mmHg or a systolic BP 180 mmHg.The participants were screened with echocardiography, and leftventricular hypertrophy (LVH), defined as LV mass index (LVMI) 130 g . m^–2, was found in 127 (68%), of whom 95 wereon antihypertensive treatment. Patients with LVH underwent amaximal bicycle ergometer exercise test and significant ST depression,indicating possible stress-induced ischaemia was found in 29men (23%). These subjects were subjected to exercise thallium-201scintigraphy, which was normal in 14 but showed reversible perfusiondefects in 15. Thus, a high prevalence of LVH (70%) was detected in male hypertensivesselected only on age and BP. In addition, although chest painon exertion excluded patients from entry, a substantial portionhad signs of ischaemia (23% on exercise ECG alone, and in 52%confirmed by thallium scan). The prevalence of these risk factorsshould be considered when evaluating hyper tensive patients.     

Non-invasive risk stratification within 48 h of hospital admission in patients with unstable coronary disease

AIMS: In this study we evaluated the prognostic value of three methodsof early risk estimation in patients with unstable coronarydisease. METHODS AND RESULTS: The methods evaluated were: clinical risk estimation at hospitaladmission, continuous ST analysis with computerized vectorcardiographyfor 24 h and serial measurements of creatinine kinase-MB for48 h. Twenty-seven (14%) of the 195 patients died or had a non-fatalinfarction within one year. Clinical risk evaluation correctlyidentified a subgroup of patients with low risk but did nototherwise predict outcome. Fifty-six (29%) patients had ST vectormagnitude episodes on vectorcardiography, 70 (38%) had threeor more episodes of ST change vector magnitude and 74 (38%)had a peak creatinine kinase-MB value of 6 µg. 1^–1or more. The even rate for patients with ST vector magnitudeepisodes (23%) was significantly higher than for those without(10%; P<0·05). For patients with and without threeor more episodes of ST change vector magnitude the event ratewas 23% and 9% respectively (P<0·05) and for patientswith and without creatinine kinase-MB 6 µg. 1^–1the event rate was 23% and 8% respectively (P<0·01).The positive predictive value of having none, either one orboth of the ST or creatinine kinase-MB markers positive wasincremental. CONCLUSIONS: Continuous vectorcardiographic monitoring of ischaemia in combinationwith serial creatinine kinase-MB measurement considerably improvesrisk stratification in unstable coronary disease.     

Spectral analysis of heart rate variability before and during episodes of nocturnal ischaemia in patients with extensive coronary artery disease

Spectral analysis of heart rate variability was used to assessautonomic nervous system activity associated with episodes ofnocturnal myocardial ischaemia in 32 patients (20 men, age 58± 9 years) with extensive coronary artery disease. Twenty-fourhour Holter tape recordings were analysed and spectral indexesof heart rate variability were computed by fast Fourier analysison 2 mm segments covering the period from 10 mm before to 10mm after each nocturnal ischaemic episode, defined as ST segmentdepression 1 mm lasting at least 4 mm. Spectral power was measuredat low frequencies (LF: 0·06–0·10 Hz) andhigh frequencies (HF: 0·15–0·40 Hz) andthe ratio LF/HF was calculated. RESULTS: A total of 30 episodes of nocturnal ischaemia were analysed.High frequency spectral power showed a clear decrease duringthe 10 mm before the onset of ischaemia, remained steady untilthe end of the episode, and returned to normal by 6 mm after.Low frequency spectral power fluctuated throughout the ischaemicepisodes with no clear pattern of variation. The low/high frequencyratio reflected mainly the changes in high frequency. CONCLUSIONS: Sympathetic predominance due to parasympathetic withdrawal isthe principal change in autonomic nervous system activity associatedwith episodes of nocturnal ischaemia. (Eur Heart J 1996; 17: 388–393)     

The relationship between early plasma atrial natriuretic factor levels and exercise performance after myocardial infarction

We tested the hypothesis that early plasma atrial natriureticfactor (ANF) values are related to subsequent functional capacityin patients with acute myocardial infarction (MI). Blood forANF determination was sampled from 90 male patients (age 66.5±9.5(mean ± SD) years) day 3 post MI. Exercise testing onan upright bicycle ergometer to symptomatic end-points was performed1 and 6 months after MI in 83 and 78 patients, respectively. A weak, but significant inverse relationship between day 3 plasmaANF levels and exercise duration after MI (1 month: r = –027,P = 0012; 6 months; r = –036, P = 0.001) was observed.In the subgroup of patients without effort-associated ischaemia,the relationship was closer (1 month; n = 38, r= –0.57,P<0.001;6 months; n = 33, r = –0.65, P<0.001). Inmultivariate analysis, with ANF, patient age and peak creatinekinase MB values as covariates, the relationship remained significant. These findings suggest that in male patients subacute plasmaANF measurements are predictive of exercise capacity followingacute MI. The relationship appears to be especially prominentin patients without effort-related ischaemia during exercise.     

Risk stratification in unstable coronary artery disease: Additive value of troponin T determinations and pre-discharge exercise tests

In 963 patients, participating in a randomized study of lowmolecular weight heparin in unstable coronary artery diseaseand followed for 5 months, troponin T was determined. In the766 patients with a pre-discharge exercise test both troponinT level and exercise test response were independent predictorsof prognosis. Cardiac death or myocardial infarction occurredin 5, 9 and 13% of the patients with a maximal troponin T levelof <0·06 (n=154), 0·06–02 (n=175) and0·2 µg . 1^–1 (n=437), respectively. Basedon exercise tolerance and occurrence of ST depression, patientswith a low (n=361), intermediate (n=325) and high risk (n=80)exercise test response were identified. In these, death or myocardialinfarction occurred in 5, 13 and 29%, respectively. The combinationof troponin T and the exercise test response allowed an evenbetter categorization into low (n=84), intermediate (n=406)and high (n=276) risk groups with 1, 7 and 20% death or myocardialinfarction, respectively. Among those 197 patients unable toperform an exercise test the incidence was 3, 16 and 27% inpatients with troponin T <0·06, 0·06–0·2and 0·2 µg . 1^–1, respectively. Thus, troponin T determinations and pre-discharge exercise testsalone and combined are valuable for risk assessment in unstablecoronary artery disease.     

Contribution of electrocardiograms, serum enzymes and history of chest pain to the diagnosis of acute myocardial infarction -- A community-based register study in North Karelia, Finland, 1972-1981

The contribution of electrocardiograms, serum enzymes and historyof chest pain to the diagnosis of acute myocardial infarction(AMI) was examined in a series of 3123 persons with a definiteacute myocardial infarction registered in a community-basedmyocardial infarction register study in North Karelia, easternFinland in 1972–1981. Criteria for chest pain history,serum enzyme and electrocardiographic findings were those usedin the WHO co-ordinated myocardial infarction register studies.The history of chest pain typical of AMI was obtained in approximately90% of both men and women in all age groups. Among persons withfirst AMI, the proportion of unequivocal ECG changes was higheramong men than in women and declined with age in both sexes(81.8% in men 20–44 years of age, 47.8% in men 75 yearsof age or more; 61.7% in women 20–54 years of age and45.6% in women 75 years of age or more) and lower among personswith recurrent AMI, but even among them it decreased with age.The proportion of serum enzyme elevations was approximately90% in all subgroups. The results of the present study reconfirmthat the contribution of elevated serum enzymes is particularlyimportant in patients with recurrent acute myocardial infarctionand old age. Elevated serum enzymes should receive greater attentionin surveillance studies aiming to detect trends in AMI incidencein populations.     

Low prevalence of coronary artery spasm in patients with normal coronary angiograms and unexplained ventricular fibrillation

Aims The aetiology of ventricular fibrillation in patients withoutidentifiable structural heart disease is unknown. Recently,a high prevalence of silent ischaemia due to coronary arteryspasm has been reported in such patients. However, in at leastone report, all patients had non-critical coronary artery lesions.Identification of coronary artery spasm as the underlying aetiologyof ventricular fibrillation has important therapeutic implications. Methods and Results We performed ergonovine provocation tests in 18 patients (14males, and four females; mean age, 36 years) with documentedventricular fibrillation in the absence of identifiable structuralheart disease who had undergone aborted sudden death. In groupI (n=7) ergo-novine provocation tests were performed at a meaninterval of 31 months (range 21–42 months) after the indexepisode. These patients had already received an implantablecardioverter defibrillator, after failed electrophysiologicallyguided antiarrhythmic therapy. In group II (n=11) the ergonovineprovocation test was performed prospectively as part of thediagnostic evaluation. All patients were off antiarrhythmicdrugs, calcium entry or beta-adrenoceptor blockers at the timeof the ergonovine provocation test. Ergonovine was administeredintravenously as a bolus injection, beginning with 0·05mgfollowed every 3min by incremental doses up to a cumulativemaximum dose of 0·45mg. Predefined end-points were: (1)recording of ischaemic ST segment shifts of 1mm in at leasttwo corresponding leads of the 12-lead electrocardiogram; (2)induction of ventricular tachycardia or ventricular fibrillation;and (3) administration of a cumulative dose of 0·45mg.A positive response to ergonovine was seen in only one patient(5%) in group I in whom there developed ST segment elevationwithout angina and a short burst of rapid ventricular tachycardia. Conclusions This study found a low prevalence of coronary artery spasm inpatients with aborted sudden death resulting from documentedventricular fibrillation and non-apparent underlying heart disease.All patients had normal coronary angiograms and a negative historyfor spontaneous episodes of chest pain. The mechanism of arrhythmogenesisin such patients remains largely unknown.     

Significance of ST-segment elevation during dobutamine-stress echocardiography in patients with acute myocardial infarction treated with thrombolysis

BACKGROUND: Stress-induced ST-segment elevation in patients with recentmyocardial infarction treated with thrombolysis has not beenextensively investigated. According to the results of previousstudies it may represent residual myocardial ischaemia or dyskinesiain the infarcted region. The aim of the study was to analysethe significance of dobutamine-induced ST-segment elevationin the infarcted area in a consecutive group of patients (n=42,41 men, mean age 53 ± 7 years) with a first acute myocardialinfarction treated with thrombolysis within 6 h from symptomsonset. METHODS AND RESULTS: All patients underwent dobutaminestress echocardiography (upto 40 µg. kg^–1. min^–1+ atropine) 7 ±3 days from the acute event and coronary arteriography within1 month from the test. Significant ST-segment elevation wasdefined as a shift 1 mm during dobutamine compared to baselinein at least two contiguous infarct-related leads; a correlationwas made between the site of ST-segment elevation and wall motionchanges during dobutamine. Dobutamine-induced ST-segment elevationin 23/42(55%) patients (group 1) while no changes were observedin 19/23 (45%) patients (group 2). Compared to group 2, group1 patients showed a higher asynergy score index (1·72± 0·24 vs 1·50 ± 0·32, P<0·02)and a higher number of asynergic segments (5·04 ±1·9 vs 4·11 ± 1·8), at baseline,a higher incidence of baseline and/or stressinduced dyskinesia(39 vs 10%, P<0·05) in the infarct-related regionand a higher percentage of occluded infarct-related arteries(48 vs 0%, P<0·001). In the 42 patients studied, asignificant correlation was found between baseline ST-segmentelevation and baseline asynergy score index (RS=0·56,P<000l) and between ST-segment elevation and asynergy scoreindex at peak stress (RS=0·55, P<0·001). Theincidence of reversible wall motion abnormalities indicativeof myocardial viability and residual myocardial ischaemia wassimilar in the two groups (87 vs 84% and 74 vs 68%, respectively),while the number of segments with irreversible akinesia indicativeof myocardial necrosis was higher in group 1 compared to group2 (1·5 ± 14 vs 0·9 ± 1·4).Among the 23 patients of group 1 with dobutamine-induced ST-segmentelevation, six had no reversible wall motion abnormalities indicativeof myocardial ischaemia; of the 17 patients with myocardialischaemia, 11 had 50% and six had 50% of basally asynergic segmentsshowing reversible wall motion abnormalities. CONCLUSIONS: In patients with recent thrombolyzed myocardial infarction dobutamine-inducedST-segment elevation is associated with a larger akinetic areain basal conditions and either with reversible wall motion abnormalitiesindicative of myocardial ischaemia or with irreversible or minimallyreversible wall motion abnormalities in the infarct area duringthe test. Thus, dobutamine echocardiography provides usefulinformation for the interpretation of stress-induced ST-segmentelevation and clinical management of these patients.     

Prevalence of coronary heart disease in Icelandic Men 1968-1986: The Reykjavik Study

The prevalence of coronary heart disease (CHD) was determinedin a general population sample of 9141 Icelandic men aged 34–79years, and the prevalence of four different forms of CHD wasestimated separately: symptomatic infarction fulfilling WHO–MONICAcriteria for definite myocardial infarction; myocardial infarctiondetected by ECG changes only (unrecognized, silent infarction);angina pectoris detected by the Rose questionnaire and associatedwith ECG manifestations of myocardial ischaemia, either at restor during exercise, but no manifestations of myocardial infarction;angina pectoris without ECG changes indicative of myocardialischaemia. The study was conducted in five stages allowing evaluationof trends from 1968–1986 Age was a major determinant of the prevalence of all forms ofCHD. Thus, the prevalence of myocardial infarction (symptomaticor silent) rose from undetectable levels in the youngest agegroup (30–34 years) to around 12% (7% symptomatic and5% silent) in the oldest group (75–79 years) and the prevalenceof all forms of CHD rose from 4% in the youngest age group to23% in the age group 70–74 years. Age-standardized comparisonwas carried out on the prevalence of the different forms ofCHD at different stages of the study in 50–64-year-oldmen who were represented in all stages of the study. There wasa gradual increase in the prevalence of myocardial infarctionfrom 3% (symptomatic and silent combined, CI 1.9–4–8)in 1968 to 4.9% in 1986 (CI 3.9–6.1) (P<0.001). Converselythere was a statistically significant fall in the prevalenceof angina pectoris, with or without ECG-manifestations of myocardialischaemia, from 11.3% (CI 8.8–14.4) in 1968 to 5% in 1986(CI 4.0–6.2) (P<0.001). This decrease was of sufficientmagnitude to more than offset the rise in infarct prevalence,resulting in a significant fall in the prevalence of all CHDfrom 14.3% (CI 11.5–17.8) in 1968 to9.9% (CI 8.5–11.5)in 1986 in 50–64-year-old men. This trend is in generalagreement with the previously reported decline in age-standardizedmortality from CHD and the incidence of myocardial infarctionin Iceland.     

Cardiothoracic ratio and relative heart volume as predictors of coronary heart disease mortality. The Whitehall study 25 year follow-up

Aim To examine the association of radiographic measures of heartsize with mortality from coronary heart disease. Methods and Results One thousand, one hundred and ninety-one male civil servantsaged 40–69 years were followed-up for mortality over 25years in relation to cardiothoracic ratio and relative heartvolume. A high cardiothoracic ratio and relative heart volumepredicted coronary (n=196 deaths) and all-cause mortality, butnot respiratory or malignant mortality. After adjustment forage, systolic and diastolic blood pressure, the highest (0·47)compared to the lowest quintile of the cardio-thoracic ratio(<0·40) was associated with a rate ratio of 1·84(95% CI 1·14–2·97) for the effect on coronaryheart disease mortality. Further adjustment for heart rate,smoking, cholesterol, angina and ECG ischaemia had little effect,reducing the rate ratio to 1·65 (95% CI 1·01–2·70).Similar rate ratios were observed for relative heart volume. Conclusions Cardiothoracic ratio within the range considered ‘normal’in clinical practice predicted coronary heart disease mortalityindependent of established coronary heart disease risk factors.The relative heart volume, which uses measurements from thelateral as well as the postero-anterior chest X-ray, did notpredict coronary heart disease any better than the cardiothoracicratio. The extent to which left ventricular mass and systolicdysfunction—pathophysiological correlates of the cardiothoracicratio and relative heart volume—are independent risk factorsfor coronary heart disease should be further investigated.     

Impact of previous percutaneous transluminal coronary angioplasty and/or stenting revascularization on outcomes after surgical revascularization: insights from the imagine study

Aim: To determine the impact of previous coronary artery revascularizationby percutaneous transluminal coronary angioplasty and/or stenting(PCI) on outcome after subsequent coronary artery bypass grafting(CABG). Methods and results: The ischaemia management with Accupril post-bypass Graft viaInhibition of the coNverting Enzyme (IMAGINE) trial, conductedbetween November 1999 and September 2004, tested whether earlyinitiation of an angiotensin-converting enzyme inhibitor post-CABG,in stable patients with LVEF 40%, would reduce cardiovascularevents. Of the 2489 patients included in the IMAGINE trial,undergoing their first operation, 430 had a history of PCI priorto surgery (PCI group), and 2059 were referred to surgery withoutprevious PCI (non-PCI group). There was a significant increasein the primary IMAGINE endpoint in the PCI group, HR = 1.53[1.17–1.98], P = 0.0016. Coronary revascularization, HR= 1.80 [1.13–2.87], P = 0.014, unstable angina requiringhospitalization, HR = 2.43 [1.52–3.89], P = 0.0002, werethe two individual components that significantly increased inthe PCI group, even when adjusted for baseline characteristics(age, sex, history of myocardial infarction or stroke, diabetes,treatment group, or off-pump surgery). Conclusion: Patients with left ventricular ejection fraction 40% havinga history of PCI prior to surgery had a worse outcome post-CABGthan those with no prior PCI. Further studies are needed toinvestigate whether these results apply for drug eluting stents.     

Effects of amlodipine on transient myocardial ischaemia in patients with a severe coronary condition treated with a beta-blocker

The purpose of this trial was to study the additional anti-ischaemiceffects of amlodipine in coronary patients with ambulant ischaemiadespite beta-blocker therapy. Beta-blockers are the most effectivedrug therapy for reducing the frequency and duration of ambulatoryischaemic episodes. However, the therapeutic advantage of combinedcalcium antagonist-beta-blocker treatment remains questionable. Three hundred and thirteen patients with documented coronaryartery disease, a positive exercise test within 6 months beforeentry and background beta-blocker therapy, were screened. Inclusioncriteria (4 episodes of transient ST segment depression of 1.0 mm and/or 20 min of ischaemia) were demonstrated in a 48h ECG during the placebo run-in period in 84 (25%) of the patients.Eighty-nine percent of the ischaemic episodes were silent. Theeligible patients were then randomized in a 2-week, double-blind,parallel group study comparing placebo to amlodipune 10 mg dailyadded to the beta-blocker. The anti-ischaemic efficacy of thecombination therapy was assessed by 48 h ECG monitoring andexercise tests. Compared to placebo, amlodipine did not significantly reduceeither the frequency (3.7±4.3 vs 4±4.8 episodesin the amlodipune group) or the duration of ambulatory ischaemia(mean duration: 43.9±57.1 vs 39.6±65.7 min, totalduration 3.1±6.7 vs 2.8±6.1 h). Exercise-inducedST segment depression tended to decrease with amlodipine (58%vs 73% in the placebo group) and the ischaemia-free workloadcapacity was increased (+1.7 stage vs 0.7 stage in the placebogroup, P=0.08). These results suggest that 2 weeks treatment with amlodipinemay not provide any additional anti-ischaemic benefit in patientswith ambulant ischaemia resistant to a beta-blocker therapy.     

Unstable coronary artery disease in post-menopausal women. Identifying patients with significant coronary artery disease by basic clinical parameters and exercise test

Background The diagnostic information from an ECG taken while at rest andan exercise test is considered less reliable in women than inmen, mostly due to a high percentage of false-positive tests.This can be explained by a lower pre-test likelihood of coronaryheart disease. Aims To evaluate the diagnostic information that can be gained frombasic clinical parameters, an ECG and exercise test in a groupof post-menopausal women with symptoms of unstable coronaryartery disease in order to identify patients with significantcoronary artery stenoses. Methods and Results We prospectively studied 200 post-menopausal women admittedto the coronary care unit with symptoms of unstable coronaryartery disease and ECG changes suggestive of ischaemia. Thediagnostic value of common risk factors, myocardial enzymesand an early exercise test were assessed. A coronary angiogramwas performed within 60 days. Median age was 67 years. On admission,38% had ST depression on an ECG taken while at rest, 76% hadT-wave inversion, and 41% increased enzyme levels. The coronaryangiogram revealed that 15% had no atherosclerosis, 14% hadatherosclerosis but no lesion 50% of luminal diameter and 71%had at least one significant stenosis. Of patients with knownindicators of atherosclerotic disease, all but one had atherosclerosisvisualized on the coronary angiogram. A relative ST depression0·1mV and a low maximum workload at exercise test werestrong predictors of significant coronary artery disease. Thepositive predictive value of ST depression was 91% and of lowmaximum workload 84%. Conclusion In post-menopausal women with signs of unstable angina and ischaemiaon an ECG taken while at rest, the prevalence of coronary atherosclerosisis high, 85%. Contrary to earlier studies, ST T-changes at theearly exercise test had a high positive predictive value, especiallyin combination with a low maximum workload with no false-positiveresults.     

Association of cardiac events with coronary artery disease detected by 64-slice or greater coronary CT angiography: A systematic review and meta-analysis

Background

The value of ≥ 64-slice coronary CT angiography (CCTA) to determine odds of cardiac death or non-fatal myocardial infarction (MI) needs further clarification.

Methods

We performed a systematic review and meta-analysis using publications reporting events/severity of coronary artery disease (CAD) in patients with suspected CAD undergoing CCTA. Patients were divided into: no CAD, non-obstructive CAD (maximal stenosis < 50%), and obstructive CAD (≥ 50% stenosis). Odds ratios with 95% confidence intervals were calculated using a fixed or random effects model. Heterogeneity was assessed using the I² index.

Results

We included thirty-two studies comprising 41,960 patients with 363 all-cause deaths (15.0%), 114 cardiac deaths (4.7%), 342 MI (14.2%), 69 unstable angina (2.8%), and 1527 late revascularizations (63.2%) over 1.96 (SD 0.77) years of follow-up. Cardiac death or MI occurred in 0.04% without, 1.29% with non-obstructive, and 6.53% with obstructive CAD. OR for cardiac death or MI was: 14.92 (95% CI, 6.78 to 32.85) for obstructive CAD, 6.41 (95% CI, 2.44 to 16.84) for non-obstructive CAD versus no CAD, and 3.19 (95% CI, 2.29 to 4.45) for non-obstructive versus obstructive CAD and 6.56 (95% CI, 3.07 to 14.02) for no versus any CAD. Similar trends were noted for all-cause mortality and composite major adverse cardiovascular events.

Conclusions

Increasing CAD severity detected by CCTA is associated with cardiac death or MI, all-cause mortality, and composite major adverse cardiovascular events. Absence of CAD is associated with very low odds of major adverse events, but non-obstructive disease significantly increases odds of cardiac adverse events in this follow-up period.     

Normal coronary flow reserve in patients with mitral valve prolapse, a positive exercise test and normal coronary arteries

We studied 12 patients (eight females and four males), ages30–46 years, with echocardiographically documented mitralvalve prolapse and clinical suspicion of coronary artery disease,based on a history of chest pain (five patients), angina-likepain (three patients), a positive exercise stress electrocardiogram(12 patients) and a focally positive thallium-201 stress perfusionscan (three patients), who were referred for cardiac catheterizationand found to have normal coronary arteries. Ten patients withoutevidence of heart disease served as controls. In all mitralvalve prolapse patients, coronary flow velocity reserve wasdetermined successively in the left anterior descending, leftcircumflex and right coronary arteries as the ratio of the maximun(after intracoronary papaverine) to the resting mean coronaryflow velocity. Coronary flow reserve values were fairly similarin the mitral valve prolapse and control patients; all 12 mitralvalve prolapse patients had normal coronary flow reserve (3.5)in all three coronary arteries with no significant differencesamong the arteries tested Mean values ± 1 standard deviationof the coronary flow reserve (mitral valve prolapse vs controlpatients) were 4.7 ± 0.5 vs 4.6 ± 0.6 for theleft anterior descending, 4.6 ± 0.4 vs 4.6 ± 0.3for the left circumflex and 4. ± 0.4 vs 4.4 ±0.5 for the right coronary artery (all P=non-significant). Thesubsets of mitral valve prolapse patients with different clinical‘ischaemic’ manifestations were similar in termsof the calculated coronary flow reserve in all three major epicardialcoronary arteries. In conclusion, this study demonstrated that an inadequate regionalcoronary flow reserve does not account for the clinical manifestationsof myocardial ischaemia and positive exercise tests in patientswith mitral valve prolapse and normal coronary arteries.