Fifteen year survival study of patients with obstructive coronary artery disease

Association of Electrocardiogram Findings With Clinical Outcomes in Patients With Chronic Coronary Syndrome: An Analysis of the ISCHEMIA Trials

OBJECTIVE

We aimed to investigate the association of electrocardiogram (ECG) findings with outcomes in patients with chronic coronary syndrome.

METHODS

This secondary analysis of the ISCHEMIA and ISCHEMIA-CKD trials divided patients with chronic coronary syndrome into two groups, those with a normal ECG tracing and abnormal ECG tracing. Repolarization abnormalities included ST-segment depression ≥ 0.5 mm and T-wave inversion ≥ 1 mm; conduction abnormalities included left and right bundle branch block (LBBB and RBBB). The primary endpoint was cardiovascular death. Outcomes were assessed using a covariate-adjusted Cox-regression model.

RESULTS

Of 5876 patients, 2901 (49.4%) had a normal and 2975 (50.6%) an abnormal ECG tracing. An abnormal ECG tracing at baseline, compared with a normal ECG tracing, was associated with an increased risk of cardiovascular death (257 of 2975 [8.6%] vs. 97 of 2901 [3.3%], adjusted hazard ratio [aHR] 2.01, 95% CI 1.58-2.55) over a median follow-up period of 3.1 years (IQR 2.1-4.2). This finding was consistent across subgroups except for patients with black skin color and current smokers, in whom an abnormal ECG was not significantly associated with increased risk of cardiovascular death. Individual ECG abnormalities (ST-segment depression [aHR 2.0, 95% CI 1.52-2.63], T-wave inversion [aHR 1.89, 95% CI 1.40-2.54], LBBB [aHR 1.74, 95% CI 1.05-2.90], and RBBB [aHR 1.52, 95% CI 1.04-2.22]) were independently associated with an increased risk of cardiovascular death.

CONCLUSION

In patients with chronic coronary syndrome, an abnormal ECG tracing was associated with an increased risk of cardiovascular death. Our findings underscore the importance of the ECG in cardiovascular risk stratification and prognostication.

TRIAL REGISTRATION

NCT01471522, BioLINCC ID 14539.

Percutaneous coronary intervention from COURAGE to ISCHEMIA and beyond

Multiple randomized clinical trials and observational studies in patients with chronic coronary artery disease have evaluated whether revascularization, in particular PCI, can reduce the incidence of future cardiovascular events and relieve angina. Perhaps the two most widely quoted trials are COURAGE and ISCHEMIA. In both trials revascularization did not reduce the incidence of cardiovascular death or non-fatal events. In both, revascularization did relieve angina, particularly in patients with severe pain. From the time of COURAGE to ISCHEMIA there were also multiple developments. In particular improved stent technology with second and third generation drug eluting stents in ISCHEMIA compared to bare metal stents in COURAGE. There was also the development of new methods to evaluate ischemia, in particular the potential surrogate fractional flow reserve. This period also saw improvement and maturation of coronary computed tomography angiography to assess coronary anatomy non-invasively. There was also greater emphasis on more intensive, guideline directed medical therapy to treat dyslipidemia and hypertension. There has also been greater recognition that not all angina is due to epicardial obstructive disease. Microvascular disease and coronary spasm are responsible for much of the symptom burden of ischemia. These data have led to a paradigm shift toward a more nuanced approach to treating stable ischemic heart disease, with less need for revascularization except in cases of particularly severe anatomic disease or unremitting symptoms while on optimal medial therapy. In recognition of the importance of disparities in cardiovascular health, it is crucial to implement preventive strategies with optimal medical therapy in the community.

Impact of periprocedural myocardial injury on long-term clinical outcomes of chronic total occlusion patients undergoing percutaneous coronary intervention: a systematic review and meta-analysis

Background:

Several studies have evaluated the long-term clinical outcomes of periprocedural myocardial injury for chronic total occlusions patients. However, the results of these studies were inconsistent. To determine whether the periprocedural myocardial injury has adverse effects on long-term clinical outcomes in chronic total occlusion patients undergoing percutaneous coronary intervention.

Methods:

We searched Cochrane Library, PubMed, and Embase for eligible articles from their date of inception up to March 2019. Long-term clinical outcomes included major adverse cardiac events, all-cause death, cardiac death, myocardial infarction, and target vessel revascularization. Odds ratios with 95% confidence intervals were calculated as summary statistics by using Review Manager software.

Results:

A total of 8 observational studies involving 5879 chronic total occlusions patients were included in this meta-analysis. These results of this meta-analysis indicated that periprocedural myocardial injury was associated with a higher risk of major adverse cardiac events (odds ratio, 1.94; 95% confidence interval, 1.22–3.08; P = 0.005), a higher risk of all-cause death (odds ratio, 1.30; 95% confidence interval, 1.02–1.64; P = 0.03), a higher risk of cardiac death (odds ratio, 2.59; 95% confidence interval, 1.41–4.78; P = 0.002), a higher risk of myocardial infarction (odds ratio, 3.07; 95% confidence interval, 1.90–4.98; P < 0.00001), and a higher risk of target vessel revascularization (odds ratio, 2.07; 95% confidence interval, 1.35–3.16; P=0.0008) than non-periprocedural myocardial injury.

Conclusion:

Periprocedural myocardial injury was associated with significantly increased risk of major adverse cardiac events, all-cause death, cardiac death, myocardial infarction, and target vessel revascularization in chronic total occlusion patients undergoing percutaneous coronary intervention at long-term follow-up.

Short-term and long-term survival in critical patients treated by helicopter emergency medical services in Finland: a registry study of 36 715 patients

OBJECTIVES

This study aimed to describe the short-term and long-term mortality of patients treated by prehospital critical care teams in Finland.

DESIGN AND SETTING

We performed a registry-based retrospective study that included all helicopter emergency medical service (HEMS) dispatches in Finland from 1 January 2012 to 8 September 2019. Mortality data were acquired from the national Population Register Centre to calculate the standardised mortality ratio (SMR).

PARTICIPANTS

All patients encountered by Finnish HEMS crews during the study period were included.

MAIN OUTCOMES

Mortalities presented at 0 to 1 day, 2 to 30 days, 31 days to 1 year and 1 to 3 years for different medical reasons following the prehospital care. Patients were divided into four groups by age and categorised by gender. The SMR at 2 to 30 days, 31 days to 1 year and 1 to 3 years was calculated for the same groups.

RESULTS

Prehospital critical care teams participated in the treatment of 36 715 patients, 34 370 of whom were included in the study. The cumulative all-cause mortality at 30 days was 27.5% and at 3 years was 36.5%. The SMR in different medical categories and periods ranged from 23.2 to 72.2, 18.1 to 22.4, 7.7 to 9.2 and 2.1 to 2.6 in the age groups of 0 to 17 years, 18 to 64 years, 65 to 79 years and ≥80 years, respectively.

CONCLUSIONS

We found that the rate of mortality after a HEMS team provides critical care is high and remains significantly elevated compared with the normal population for years after the incident. The mortality is dependent on the medical reason for care and the age of the patient. The long-term overmortality should be considered when evaluating the benefit of prehospital critical care in the different patient groups.

Utilization of stress echocardiography in patients with multivessel coronary artery disease

OBJECTIVE

The purpose of this study was to evaluate the role of stress echocardiography in the risk stratification and prognosis of patients with multivessel coronary artery disease (CAD).

BACKGROUND

Stress echocardiography is an established technique for diagnosis, risk stratification, and prognosis of patients with known or suspected CAD.

METHODS

We evaluated 409 patients (65 ± 10 years; 63% men) referred for stress echocardiography (45% treadmill, 55% dobutamine), who underwent stress echocardiography and coronary angiography within 3 months. All patients had multivessel CAD as defined by coronary stenosis (≥50% left main or ≥70% in two or more major epicardial vessels or branches). The left ventricle was divided into 16 segments and was scored on a five-point scale of wall motion. Patients with abnormal results on stress echocardiography were defined as those with stress-induced ischemia (increase in wall motion score of ≥1 grade).

RESULTS

Follow-up (3.1 ± 1.3 years) for nonfatal myocardial infarction (n = 35) and cardiac death (n = 25) was obtained. In patients with multivessel CAD, stress echocardiography effectively risk-stratified normal (no ischemia, n = 83) vs. abnormal (ischemia, n = 326) groups for cardiac events (event rate 1.9 vs. 5.4%/year; P < 0.01). Multivariable Cox proportional-hazards regression model identified stress-induced ischemia (hazard ratio 5.5, 95% confidence interval 1.9-15.9, P = 0.002) as the most significant predictor of adverse cardiac events. A stepwise Cox proportional-hazards model demonstrated significant incremental prognostic value of stress echocardiography over clinical variables, stress electrocardiography and resting left ventricular function (P < 0.0001), with the highest global chi-square value.

CONCLUSIONS

In patients with angiographically significant multivessel CAD, despite normal-stress echocardiography, there was an intermediate cardiac event rate (1.9%/year); abnormal-stress echocardiography identified a high-risk group (5.4%/year); and stress echocardiography provided incremental prognostic value for risk stratification and prediction of cardiac events.

Prognostic value of stress echocardiogram in patients with angiographically significant coronary artery disease

The purpose of this study was to evaluate the prognostic value of stress echocardiography in patients with angiographically significant coronary artery disease (CAD). Two hundred sixty patients (mean age 63 ± 10 years, 58% men) who underwent stress echocardiography (41% treadmill, 59% dobutamine) and coronary angiography within 3 months and without intervening coronary revascularization were evaluated. All patients had significant CAD as defined by coronary stenosis ≥70% in major epicardial vessels or branches (45% had single-vessel disease, and 55% had multivessel disease). The left ventricle was divided into 16 segments and scored on a 5-point scale of wall motion. Patients with abnormal results on stress echocardiography were defined as those with stress-induced ischemia (increase in wall motion score of ≥1 grade). Follow-up (3.1 ± 1.2 years) for nonfatal myocardial infarction (n = 23) and cardiac death (n = 6) was obtained. In patients with angiographically significant CAD, stress echocardiography effectively risk stratified normal (no ischemia, n = 91) in contrast to abnormal (ischemia, n = 169) groups for cardiac events (event rate 1.0%/year vs 4.9%/year, p = 0.01). Multivariate logistic regression analysis identified multivessel CAD (hazard ratio 2.53, 95% confidence interval 1.16 to 5.51, p = 0.02) and number of segments in which ischemia was present (hazard ratio 4.31, 95% confidence interval 1.29 to 14.38, p = 0.01) as predictors of cardiac events. A Cox proportional-hazards model for cardiac events showed small, significant incremental value of stress echocardiography over coronary angiography (p = 0.02) and the highest global chi-square value for both (p = 0.004). In conclusion, in patients with angiographically significant CAD, (1) normal results on stress echocardiography conferred a benign prognosis (event rate 1.0%/year), and (2) stress echocardiographic results (no ischemia vs ischemia) added incremental prognostic value to coronary angiographic results, and (3) stress echocardiography and coronary angiography together provided additive prognostic value, with the highest global chi-square value.

Prognostic value of cardiac troponin-I or troponin-T elevation following nonemergent percutaneous coronary intervention: a meta-analysis

OBJECTIVES

The aim of this meta-analysis was to assess the prevalence and prognostic value regarding mortality of cTnT or cTnI elevations after nonemergent percutaneous coronary intervention (PCI) in a large number of cohort/registry studies.

BACKGROUND

Routine cardiac troponin measurement after elective PCI has been controversial among interventionalists. Recent studies have provided conflicting data in regard to predictive value of cardiac troponin-T (cTnT) and troponin-I (cTnI) elevation after non-emergent PCI.

METHODS

Electronic and manual searches were conducted of all published studies reporting on the prognostic impact of cTnT or cTnI elevation after elective PCI. A meta-analysis was performed with all-cause mortality at follow-up as the primary endpoint.

RESULTS

We identified 22 studies, involving 22,353 patients, published between 1998 and 2009. Postprocedural cTnT and cTnI were elevated in 25.9% and 34.3% of patients, respectively. Follow-up period ranged from 3 to 67 months (mean: 17.7 ± 14.9 months). The results showed no heterogeneity among the trials (Q-test: 25.39; I(2) : 17%; P = 0.23). No publication bias was detected (Egger's test: P = 0.16). The long-term all-cause mortality in patients with cTnI or cTnT elevation after PCI (5.8%) was significantly higher when compared to patients without cTnI or cTnT elevation (4.4%); OR 1.45 (95% CI: 1.22-1.72), P < 0.01. In addition, the postprocedural composite adverse clinical events of all-cause mortality or myocardial infarction (MI) in patients with cTnI or cTnT elevation after PCI (9.2%) was significantly higher when compared to patients without cTnI or cTnT elevation (5.3%); OR 1.77 (95% CI: 1.48-2.11), P < 0.01.

CONCLUSIONS

The current meta-analysis indicates that cTnI or cTnT elevation after nonemergent PCI is indicative of an increase in long-term all-cause mortality as well as the composite adverse events of all-cause mortality and MI. Efforts to routinely monitor periprocedural cTn levels along with more intensive outpatient monitoring/treatment of patients with cTn elevations may help to improve the long-term adverse outcomes in these patients following non-emergent PCI.

Renal function is associated with arterial stiffness and predicts outcome in patients with coronary artery disease

BACKGROUND

Arterial stiffness (AS) is associated, and a predictor of, outcome in patients with cardiovascular and renal disease.

AIM

In this study, we estimated glomerular filtration rate (eGFR) and measured indices of AS in patients with suspected coronary artery disease (CAD), and assessed their predictive value on outcome.

DESIGN

Prospective cohort study.

METHODS

AS was measured using pulse wave velocity (PWV) and pulse wave analysis in patients with no known renal disease who had recently undergone coronary angiography. Renal function was assessed using serum creatinine concentration [creat](sr) and eGFR (Cockcroft & Gault, C&G). The primary endpoint was a combination of hospitalization due to cardiovascular disease and all-cause mortality.

RESULTS

Two hundred eighty-four subjects (210 men, 74 women, mean age 62 years) were followed-up for a mean of 1.5 years. PWV was negatively associated with eGFR (r(2) = 0.09, P < 0.001), even in patients with an eGFR > or =60 ml/min/m(2) (r(2) = 0.04, P < 0.01). PWV was determined by age, heart rate, systolic blood pressure, body mass index and [creat](sr) (r(2) = 0.38, P < 0.001). A lower eGFR (P < 0.01), PWV above the median (P < 0.05) and degree of CAD (P < 0.001) predicted a shorter time to the primary endpoint. eGFR and degree of CAD remained independent determinants of outcomes (P < 0.01), even in patients with normal renal function (P < 0.01).

CONCLUSION

This study suggests that even minor reductions in eGFR, within the normal range, are an additional independent risk marker in patients with CAD.

Renal dysfunction is the most important predictor of the extent and severity of coronary artery disease in patients with diabetes mellitus

OBJECTIVES

Diabetic patients tend to have more extensive and diffuse coronary artery disease (CAD) that may contribute to the less favorable outcomes in them. The aim of this study was to elucidate the predictors of the angiographic severity and extent of CAD in patients with diabetes.

METHODS

A total of 203 diabetic patients (116 men; mean age, 61.9+/-10.8) who were referred for a first coronary angiogram were included. The extent and severity of CAD was assessed in several ways. The first was a simple classification in one-vessel, two-vessel, and three-vessel disease scoring system. The total numbers of segments with > or = 20 and > or = 50% stenosis were calculated as CASS 20 and CASS 50 scores, respectively. Hamsten and Gensini scores were also calculated.

RESULTS

Of the 203 patients included in the study, 175 (86.2%) had CAD. Multivariate ordinal logistic regression analysis showed that age (Wald 5.741, P=0.017), glomerular filtration rate (Wald 5.032, P=0.025), previous myocardial infarction (Wald 10.955, P=0.001), and family history of CAD (Wald 7.236, P=0.007) were independent predictors of the severity of CAD, as assessed by the clinical zero-vessel to three-vessel disease scoring system. On stepwise multiple linear regression analysis, glomerular filtration rate was an independent predictor of the CASS 20 (r=-0.221, P=0.004), CASS 50 (r=-0.239, P=0.005), Gensini (r=-0.328, P<0.001), and Hamsten (r=-0.320, P<0.001) scores. Previous myocardial infarction was an independent predictor of the CASS 50 (r=0.355, P<0.001), Gensini (r=0.350, P<0.001), and Hamsten (0.256, P<0.001) scores. Age and sex were independent predictors for the CASS 50 (r=0.174, P=0.039; r=0.172, P=0.016, respectively) and Hamsten (r=0.212, P=0.011; r=0.244, P=0.001, respectively) scores.

CONCLUSION

Renal function is one of the most important factors associated with the extent and severity of coronary atherosclerosis, whereas classical coronary risk factors and the degree of metabolic control were not associated with the severity of coronary atherosclerosis in diabetic patients.

C-reactive protein and angiographic characteristics of stable and unstable coronary artery disease: data from the prospective PREVEND cohort

AIMS

High sensitive-C-reactive protein (hs-CRP) is associated with coronary risk, which may be explained by an association with (unstable) coronary artery disease (CAD). Until now, histopathological and angiographic studies have failed to consistently demonstrate a strong relationship. However, most of these studies were limited by a cross-sectional design. Our aim was to prospectively evaluate the association between hs-CRP and plaque instability. Therefore, firstly, we investigated the relation between hs-CRP measured long before coronary angiography (CAG) and angiographic characteristics of stable and unstable CAD. In addition, we investigated the association with coronary events during follow up in the total PREVEND population.

METHODS AND RESULTS

Of the population based Prevention of Renal and Vascular Endstage Disease (PREVEND) study, 8139 subjects without previous documented CAD were followed for the incidence of CAG and coronary events from 1997 to 2003. For the qualitative angiographic analysis, 216 CAGs were available. Mean time to CAG was 37+/-19 months. The 864 coronary vessels were graded as follows: 436 coronary vessels as normal, 175 as non-obstructive CAD, 179 as stable obstructive CAD and 74 as unstable obstructive CAD. Multilevel ordinal regression analysis was performed to study associations between baseline clinical variables and angiographic findings. Hs-CRP contributed significantly to the multivariate model after adjustment for age, gender, smoking, lipids and blood pressure. In 8139 subjects, 201 (2.5%) first coronary events occurred during follow up. Cox survival analysis showed age- and sex-adjusted hazard ratios for hs-CRP 1-3 and >3mg/L of, respectively, 1.26 (95% CI 0.67-2.40) and 3.16 (95% CI 1.26-3.16), relative to hs-CRP <1mg/L.

CONCLUSION

In the prospective PREVEND study of subjects without previous documented CAD, hs-CRP levels at baseline were associated with angiographic characteristics and clinical consequences of plaque instability during follow up. This observation supports the concept that hs-CRP significantly contributes to coronary atherogenesis.

Specificity of vascular reactivity and remodeling after repeated endothelial injury in a swine model

We investigated the difference in vascular responses and remodeling between coronary and iliac arteries after repeated endothelial denudation. Endothelial denudation of the left anterior descending coronary artery (LAD) and the right common iliac artery (RIA) was repeated 4 times twice a month using a Fogarty catheter in 21 pigs. Vascular responses to vasoactive drugs were evaluated as % luminal diameter changes on contrast angiography 2 weeks after the last denudation. Corresponding nondenuded sites, ie, the left circumflex coronary artery (LCX) and the left common iliac artery (LIA), were used as references. Acetylcholine (1 microg/kg) did not constrict the LCX (0 +/- 1%) and the LAD (1 +/- 1%, P < 0.05), whereas it constricted the RIA (20 +/- 6%) but not the LIA (-3 +/- 3%, P < 0.01). Alternatively, serotonin (10 microg/kg) constricted the LAD strikingly (88 +/- 5%, P < 0.01 versus LCX and RIA), as well as the RIA (35 +/- 10%, P < 0.05 versus LIA). Vasodilator responses to substance P and isosorbide dinitrate were not different after injury in both arteries. The intima-to-media ratio and adventitia-to-media ratio of the relevant site in cross section of tissue sample from LAD were greater than those from LCX, and were more prominent than those from RIA. The results show that vascular tone regulation after the endothelial injury and vascular remodeling might be altered in a vessel-specific manner.

Relation of progression of coronary artery atherosclerosis to risk of cardiovascular events (from the Monitored Atherosclerosis Regression Study)

We investigated whether change in coronary artery atherosclerosis as measured by quantitative coronary angiography is related to cardiovascular event risk. Although many studies have demonstrated the effectiveness of statins in decreasing atherosclerotic progression and cardiovascular event risk, a relation between coronary atherosclerotic progression and event risk has not been documented in clinical trials that have evaluated statin therapy. The Monitored Atherosclerosis Regression Study (MARS) was a randomized, double-blind, placebo-controlled trial designed to test whether lovastatin would decrease coronary atherosclerotic progression as measured by quantitative coronary angiography. We followed 173 subjects in the MARS who had minimum luminal diameter and percent diameter stenosis measured at the beginning and end of a 2-year intervention. Postintervention follow-up events over a mean period of 9.4 years were reported by subjects and verified by medical records. Two-year percent stenosis and minimum luminal diameter changes were tested in relation to clinical event risk in multivariate Cox's regression models. Events ascertained were (1) coronary death and myocardial infarction, (2) coronary death, myocardial infarction, coronary artery bypass grafting, and percutaneous transluminal coronary angioplasty, and (3) any cardiovascular event. Increased percent stenosis was associated with significantly increased hazard ratios (HRs) in all event categories (category 1 HR 1.55 per SD percent stenosis, p <0.01; category 2 HR 1.58, p <0.01; category 3 HR 1.47, p = 0.01). Conversely, event risks were decreased for subjects who had increased minimum luminal diameter (category 1 HR 0.79, p = 0.04) and were not associated with category 2 (HR 0.79, p = 0.12) or category 3 (HR 0.81, p = 0.17). These results indicate that quantitative coronary angiographic changes are associated with cardiovascular events and support the long-term benefit of early intervention to decrease atherosclerosis.

Comprehensive imaging of coronary artery disease: impact on contemporary treatment approaches

Coronary artery disease remains a major cause of mortality. Together with novel therapeutic and preventive approaches, important advances of coronary imaging are currently emerging. This article describes the status of modern coronary imaging and outlines expected future developments.

Assessing the prognostic value of coronary endothelial function in patients referred for a first coronary angiogram

At present, the value of endothelial function as a prognostic tool has been evaluated only in selected groups of patients with mild or minor coronary artery disease, not in the complete spectrum of patients presenting with angina. The objective of this study was to evaluate whether endothelium-dependent vasodilation of the coronary arteries in response to acetylcholine infusion as a marker of endothelial function would have prognostic value in patients referred for a first coronary angiogram. The data suggest that endothelial function assessment does not contribute to the prediction of outcomes in patients referred for a first coronary angiogram.

Use of a simple clinical score to predict prognosis of patients with normal or mildly abnormal resting electrocardiographic findings undergoing evaluation for coronary artery disease

OBJECTIVE

To determine whether a simple clinical score, which was shown previously to predict the likelihood of severe coronary artery disease (CAD) in patients referred for coronary angiography, could predict prognosis in a separate cohort of patients with normal or mildly abnormal findings on their resting electrocardiogram (ECG) who were undergoing noninvasive evaluation for possible CAD.

PATIENTS AND METHODS

The study group included 2255 symptomatic patients with normal (n=1466) or mildly abnormal (nonspecific ST-T-wave abnormalities; n=789) findings on their resting ECG who were referred for exercise thallium testing between 1989 and 1991. Follow-up was 94% complete at a mean +/- SD duration of 6.9+/-1.5 years. The clinical score, which ranged from 0 (lowest risk) to 10 (highest risk), was calculated by awarding 1 point each for male sex, history of myocardial infarction, typical angina, diabetes mellitus, insulin use, and each decade of age older than 40 years.

RESULTS

In each ECG group, the clinical score was a significant predictor of cardiac death, nonfatal myocardial infarction, or late revascularization, considered individually or combined, unadjusted or with adjustment for age. Most patients had a score lower than 5; these patients had an excellent 5-year cardiac survival rate (99.7% for the normal ECG findings group and 98.8% for the ST-T-wave abnormalities group). The small subset of patients with a score higher than 5 had a much lower 5-year survival rate (923% for the 8% of patients with normal ECG findings and 86.6% for the 14% of patients with ST-T-wave abnormalities). For patients with a score of 5, the 5-year survival rate was 97.7% for the normal ECG findings group and 95.9% for the ST-T-wave abnormalities group.

CONCLUSION

In symptomatic patients with known or suspected CAD and normal or mildly abnormal resting ECG findings, this simple, easily computed clinical score is a useful and valid tool to help determine prognosis.

Relation between coronary atherosclerotic plaque burden and cardiac enzyme elevation following percutaneous coronary intervention

Several studies have reported that elevation of cardiac creatine kinase (CK) enzymes after percutaneous coronary intervention (PCI) is associated with an increase in cardiac morbidity and mortality during follow-up. However, it remains unclear if enzyme elevation contributes to the adverse outcomes or is simply a marker for adverse events. We conducted a case-control study to determine if angiographically determined atherosclerotic plaque burden correlated with CK elevation. Patients (cases, n = 23) with CK elevation after PCI were identified along with 46 age- and gender-matched controls without CK elevation. Detailed angiographic analysis quantified the percentage of coronary artery length with any luminal irregularity, a surrogate for plaque burden. The CK elevation group was characterized by a greater number of smokers (65% vs 33%, p = 0.02), more thrombus-containing lesions (22% vs 2.2%, p = 0.014), and more frequent abrupt closure (13% vs 0%, p = 0.03). In addition, the case group had a 50% increase in atherosclerotic plaque burden compared with controls (30 +/- 14% vs 20 +/- 14%, p = 0.006). These data suggest that CK elevation after PCI is a marker for more extensive atherosclerosis, which may explain the worse prognosis of these patients.

Independent and incremental value of coronary artery calcium for predicting the extent of angiographic coronary artery disease: comparison with cardiac risk factors and radionuclide perfusion imaging

OBJECTIVES

The study was done to test the ability to predict the extent of angiographically determined coronary artery disease (CAD) by quantification of coronary calcium using electron-beam computed tomography (EBCT) and to compare it with more conventional parameters for delineating the angiographic extent of CAD, that is, cardiovascular risk factors and radionuclide single-photon emission computed tomography (SPECT).

BACKGROUND

The angiographic extent of CAD is a powerful predictor of subsequent events. Use of EBCT may be able to define it by virtue of its ability to determine plaque burden.

METHODS

We examined 308 patients presenting with suspected but not previously known CAD who underwent selective coronary angiography. As measures of the angiographic extent of CAD, coronary artery greater even 20 (CAGE > or =20) and CAGE > or =50 scores represented the total number of coronary segments with > or =20% or > or =50% stenoses, respectively. The EBCT-derived total calcium scores were obtained in 291 patients, risk factors as defined by the National Cholesterol Education Program in 239 patients, and SPECT scans in 136 patients.

RESULTS

Using multiple linear regression analysis, total calcium scores were better independent predictors of both CAGE > or =20 and CAGE > or =50 scores than either a SPECT-derived radionuclide perfusion score or the risk factors age, male gender and ratio of total/high-density lipoprotein (HDL) cholesterol. The association between EBCT and angiographic scores remained highly significant after excluding the influence of all interrelated risk factors and SPECT variables (r = 0.65; p < 0.001 for CAGE > or =20 scores, r = 0.50; p < 0.001 for CAGE > or =50 scores).

CONCLUSIONS

Coronary calcium predicts the angiographic extent of CAD in symptomatic patients and provides independent and incremental information to the more conventional clinical parameters derived from SPECT or risk assessment.

Clinical and sequential angiographic follow-up six months and 10 years after successful percutaneous transluminal coronary angioplasty

Sequential angiographic follow-up is needed for interpreting coronary events that occur after successful percutaneous translumial coronary angioplasty (PTCA). One hundred eight consecutive patients who had undergone successful dilatation were followed for 10 years, and quantitative sequential angiograms were recorded at 6 months (n = 101) and 10 years (n = 68). The 10-year event rate was: 5.8 +/- 2.4% for cardiac death, 9.7 +/- 3.3% for Q-wave acute myocardial infarction, 18.3 +/- 4.5% for additional surgery, and 22.4 +/- 4.9% for repeated angioplasty. Using Cox's proportional-hazards regression, multivessel coronary artery disease (CAD) (RR 5.6; 95% confidence intervals [CI] 1.2 to 24.7; p = 0.02), restenosis within 6 months (RR 7.8; 95% CI 3.1 to 20.0; p = 0.0001), and CAD progression over 10 years (RR 10.6; 95% CI 1.3 to 87.1; p = 0.004) were the strongest predictors of all-cause death, repeated PTCA, and additional surgery, respectively, after controlling for age and coronary risk factors. The minimal luminal diameter of 48 narrowings with complete sequential angiographic follow-up and without restenosis remained stable from 6 months (2.13 +/- 0.60 mm) to 10 years (2.18 +/- 0.61 mm). Disease progression was similar in nondilated arteries and dilated arteries (32% vs 30%). The 10-year risk of coronary events was higher in patients with baseline multivessel CAD than in those with 1-vessel CAD because of more frequent progression of CAD (RR 3.8; 95% CI 1.6 to 6.8; p = 0.001). Thus, early cardiac events after successful PTCA were related to restenosis, and late events to CAD progression. Nevertheless, after the restenosis period, the target lesion remained stable for the next 10 years. Coronary disease progression was not related to the angioplasty procedure.

Natural history of myocardial infarction and angina pectoris in a general population sample of middle-aged men: a 16-year follow-up of the Primary Prevention Study, Göteborg, Sweden

OBJECTIVES

Although many studies have described prognosis in patients with coronary heart disease (CHD), few have compared outcome in men with clinical evidence of CHD with healthy men from the general population over an extended follow-up. This study aimed to compare long-term prognosis in men with a history of myocardial infarction (MI) and in men with angina pectoris (AP) without MI, with men without clinical signs of CHD.

DESIGN

Longitudinal general population study.

SETTING

City of Göteborg, Sweden.

SUBJECTS

From a general population sample, 195 men who had survived an MI for 0-19 years (median 3 years) and 314 men with AP but no MI (uncomplicated AP) at baseline in 1974-77 were identified and compared with 6591 men without clinical coronary disease. All were aged 51-59 years. Incident non-fatal and fatal cases occurring until the beginning of 1983 were also followed (n = 317).

MAIN OUTCOME MEASURES

Death from CHD, from other causes and from all causes during a follow-up of at least 16 years.

RESULTS

Overall survival was 72% amongst men without coronary disease, 53% amongst men with uncomplicated AP and 34% amongst men with past MI at baseline. In survivors of MI the risk-factor-adjusted relative risk (RR) of coronary death during follow-up was 6.67 (95% confidence interval (CI) 5.29-8.39), of dying from non-cardiovascular causes 1.35 (0.96-1.91), and of dying from any cause 3.20 (2.67-3.83). During the first 4 years after the baseline examination, the adjusted RR of CHD death was 15.96 (10. 29-24.74), and of dying from any cause 5.22 (3.68-7.41). During the last 4 years of follow-up, relative risk was still 5.87 (3.44-10.01) for CHD death and 2.93 (2.05-4.18) for death from any cause. In men with uncomplicated AP, the adjusted relative risk of CHD death during the first 4 years was 4.05 (2.27-7.22) and 3.23 (2.10-4.96) during the last 4-year period. After the first year, the incident MI cases had the same average annual mortality (about 5%) as the prevalent cases.

CONCLUSIONS

In survivors of MI, mortality risk remained high even after an extended follow-up. Men with angina had a better prognosis, but still a compromised survival compared with the general population.

Association between coronary angiograms and cardiac events--a prospective 3-year follow-up. INTACT-Investigators. International Nifedipine Trial on Antiatherosclerotic Therapy

The correlation between extent and severity of coronary artery disease as documented by quantitative coronary angiography and the incidence of cardiac events within 3 years was analyzed from a prospective study. In 73 out of 419 patients, 89 events occurred comprising 10 cardiac deaths, 15 non-fatal myocardial infarcts, 26 cases of unstable angina, and 38 coronary revascularization procedures (bypass graft operation or angioplasty). The incidence of any event correlated with the baseline number of all stenoses and high-grade stenoses (> or =20% and > or =50% diameter stenosis, respectively) (P<0.05). With respect to specific events, non-fatal myocardial infarcts and revascularization procedures were correlated with the number of all stenoses (P<0.05), but not with high-grade stenoses. Specification of coronary arteries revealed correlation of non-fatal myocardial infarcts and revascularization procedures with the number of high-grade stenoses in the left anterior descending artery. Finally, baseline left ventricular ejection fraction was found to be lower in patients who died of cardiac causes than in the remaining patients (49 +/- 10% vs. 67 +/- 13%; P<0.001). In conclusion, the total coronary stenosis burden seems to predict the incidence of subsequent cardiac events even better than the number of high-grade stenoses. Only in the left anterior descending artery high-grade stenoses seem to cause myocardial infarcts within a relatively short period of time justifying short-term revascularization in these patients.

Comparison of dobutamine and treadmill exercise echocardiography in inducing ischemia in patients with coronary artery disease

OBJECTIVES

We sought to compare the magnitude of ischemia precipitated by both treadmill exercise and dobutamine stress echocardiography.

BACKGROUND

Although it is alleged that dobutamine stress produces ischemia similar in degree and extent to that produced during treadmill exercise, a direct comparison with treadmill exercise, the most common form of exercise, has not been performed.

METHODS

Eighty-five consecutive patients with known coronary artery disease underwent both stress tests on the same day, in random order.

RESULTS

Sixty-two patients (73%) had positive results on exercise echocardiography compared with 53 (62%) who had positive results on dobutamine stress (p = NS). Of the 53 patients with positive dobutamine test results, wall motion abnormalities appeared after the addition of atropine in 35 patients (66%). During dobutamine infusion, 22 patients (26%) had a hypotensive response that was reversed in 16 by prompt administration of atropine. At peak dobutamine-atropine stress, heart rate was higher than that at peak exercise (p < 0.001), whereas systolic blood pressure and rate-pressure product were higher at peak exercise than at peak dobutamine-atropine stress (p = 0.0001). In the 53 patients with positive results on both tests, peak wall motion score index was greater with treadmill exercise than with dobutamine-atropine infusion ([mean +/- SD] 1.73 +/- 0.45 vs. 1.57 +/- 0.44, p < 0.001).

CONCLUSIONS

Echocardiography immediately after treadmill exercise induces a greater ischemic burden than dobutamine-atropine infusion. In the clinical setting, exercise echocardiography should therefore be chosen over dobutamine echocardiography for diagnosing ischemia, when possible. When dobutamine echocardiography is used as an alternative modality, maximal heart rate should always be achieved by the addition of atropine.

Implication of myocardial lactate metabolism during coronary artery bypass grafting

Sixty-six consecutive patients with coronary artery disease were analysed in terms of myocardial lactate extraction during cardiac surgery. Sixteen patients had left main coronary heart disease and 50 were without such disease. Mean (s.d.) lactate extraction during empty beating in patients with and without left main coronary tract disease was -29.8(67)% and 12.0(15.3)%, respectively (P<0.001). No significant differences in lactate extraction were recognized during 15 min of reperfusion. Mean (s.d.) preoperative values of haemoglobin were 11.2(1.0) g/dl and these fell to 6.5(0.9) g/dl in an empty beating state during cardiopulmonary bypass (P<0.001). There was no significant difference between the two groups in preoperative and postoperative left ventricular stroke work index. An empty beating state before aortic clamping could induce unexpected ischaemia in the heart with left main coronary tract disease. A short duration of this ischaemic state does not influence functional recovery; however, exposing the left main coronary artery diseased heart to such a condition for long periods would be dangerous.

Comparison of dobutamine stress echocardiography and 99m-technetium sestamibi SPECT myocardial perfusion scintigraphy for predicting extent of coronary artery disease in patients with healed myocardial infarction

This study compares the value of dobutamine stress echocardiography and 99m-technetium methoxyisobutyl-isonitrile (MIBI) single-photon emission computed tomography (SPECT) in the assessment of extent and location of coronary narrowing in patients with healed myocardial infarction. Dobutamine (up to 40 microg/kg/ min)-atropine (up to 1 mg) stress echocardiography (DSE) in conjunction with MIBI SPECT was performed in 72 patients (52 men, mean age 57 +/- 11 years) with healed myocardial infarction referred for evaluation of myocardial ischemia. Ischemia was defined as new or worsened wall motion abnormalities at DSE and reversible perfusion defects at MIBI SPECT. Significant stenosis (> or = 50% luminal diameter stenosis) of the infarct-related artery was detected in 45 patients and of other coronary arteries in 22 patients. Sensitivity and specificity of remote ischemia for diagnosis of remote coronary stenosis were 68% (95% confidence interval [CI] 57 to 80) and 93% (CI 86 to 99) for DSE, and 64% (CI 52 to 76), and 90% (CI 83 to 98) for MIBI SPECT, respectively. The positive predictive value and specificity of peri-infarction ischemia for the diagnosis of infarct-related artery stenosis were 89% (CI 81 to 97) and 82% (CI 73 to 92) for DSE, and 87% (CI 79 to 95) and 82% (CI 73 to 92) for SPECT, respectively. The agreement between both techniques was higher for the diagnosis of remote than peri-infarction ischemia (84% vs 66%, p = 0.02). It is concluded that in patients with myocardial infarction undergoing dobutamine stress testing, both echocardiography and MIBI SPECT are clinically useful methods for the diagnosis of remote and infarct-related coronary artery stenosis.

Angiographic severity of coronary narrowing is a surrogate marker for the extent of coronary atherosclerosis

Most acute coronary events occur because of narrowings at sites of angiographically minor plaque. Despite this, angiograms are reported in terms of the number of coronary arteries with severe narrowings. Disease severity is correlated with prognosis, but this may simply be due to a strong positive correlation between the severity and extent of coronary atheroma. We therefore aimed to assess the relation between the severity and the extent of coronary atherosclerosis. Coronary angiograms of 350 consecutive patients referred for elective cardiac catheterization were analyzed. Two independent observers calculated the number of arteries with > or = 70% stenosis, a disease severity score, and an extent score (percentage of the coronary artery length with any luminal irregularity). There were no obstructive stenoses in 123 patients (35%); 91 (26%) had 1-vessel disease, 81 (23%) had 2-vessel disease, and 55 (16%) had 3-vessel coronary artery disease. The median severity score was 1 (lower, upper quartile 0, 3; range 0 to 8), and the median extent score was 66% (lower, upper quartile 32, 83; range 0% to 100%). There was a strong linear relation between severity score and extent score (r = 0.62, p < 0.001); however, the data were better described by 2 intersecting straight lines, with a steeper increase in disease severity when the extent score was between 80% and 90% (F1;121 = 6.9, p = 0.001). The severity of coronary disease is therefore significantly correlated with disease extent. This may explain the observed relation between the number of arteries with obstructive stenoses and subsequent risk, even though most events occur at sites of minor plaque.

Accuracy of dobutamine stress echocardiography for the diagnosis of coronary artery stenosis in patients with myocardial infarction: the impact of extent and severity of left ventricular dysfunction

OBJECTIVES

To assess the value of dobutamine stress echocardiography (DSE) in the prediction of the extent and location of coronary artery stenosis in symptomatic patients with old myocardial infarction and to study the impact of the severity of resting wall motion abnormalities (WMA) on the diagnostic accuracy of the test.

PATIENTS

One hundred and thirty two symptomatic patients with old myocardial infarction.

METHODS

DSE (up to 40 micrograms/kg/min, with atropine up to 1 mg) was performed in all patients. Ischaemia was defined as new or worsened WMA. For each coronary artery, regional wall motion in the corresponding territory was classified as normal, mildly, moderately, or severely impaired according to the wall motion score index. Significant coronary stenosis was defined as > or = 50% diameter stenosis.

RESULTS

A positive DSE for ischaemia occurred in 87 of 111 patients with and three of 21 patients without coronary artery stenosis (sensitivity = 78%; CI 71 to 86, specificity = 86%; CI 79 to 92, accuracy = 80%; CI 73 to 87). The accuracy for the diagnosis of individual coronary stenosis was 69% in the presence of normal wall motion and 74%, 74%, and 61% respectively when there was mild, moderate, and severe WMA in the corresponding territories (P = NS). The sensitivity was higher in presence of mild or moderate WMA (73%) than with normal wall motion (53%) or severe WMA (56%, P < 0.05 in both). In territories subtended by a stenotic artery, the regional wall motion score index was not different with or without ischaemia.

CONCLUSION

DSE had a good overall accuracy for the diagnosis of coronary artery stenosis in symptomatic patients with old myocardial infarction. The presence of resting WMA did not limit DSE as a method of eliciting myocardial ischaemia and diagnosing significant coronary artery stenosis in patients with old myocardial infarctions.

Persistent transient myocardial ischemia despite beta-adrenergic blockade predicts a higher risk of adverse cardiac events in patients with coronary artery disease

OBJECTIVES

We evaluated the prevalence and prognostic significance of transient myocardial ischemia despite beta-adrenergic blockade in patients with coronary artery disease.

BACKGROUND

Persistence of transient ischemia despite therapy may correspond to a subset of high risk patients with coronary disease. The impact of beta-blocker withdrawal in these patients remains unknown.

METHODS

Patients (n = 313) with documented coronary artery disease and beta-blocker therapy, with (group I, n = 84) or without (group II, n = 229) transient ischemia on ambulatory electrocardiographic monitoring, were followed up during 21 +/- 9 months for cardiac events (death, myocardial infarction, percutaneous transluminal coronary angioplasty, coronary artery bypass surgery and worsening angina). Occurrence of events was compared by log-rank test.

RESULTS

The number of coronary stenoses did not differ significantly between groups I and II. Beta-blocker therapy was discontinued more frequently during follow-up in group II (25% vs. 14% in group I, p = 0.04). Cumulative percentage of death or myocardial infarction, or both, tended to be higher in group I a 30 months (17% vs. 5% in group II, p = 0.09). Coronary angioplasty and bypass surgery were significantly more frequent in group I (p = 0.01 and 0.0008, respectively). Transient ischemia was associated with a higher cumulative probability of adverse events (p = 0.004). The number of coronary stenoses, presence of transient ischemia and beta-blocker withdrawal were the only significant prognostic factors of cardiac events in the Cox model. In group I patients, the relative hazard of cardiac events was increased threefold when beta-blocker therapy was interrupted.

CONCLUSIONS

These data suggest that 1) the occurrence of transient ischemia despite beta-blocker therapy identifies a subset of high risk patients with coronary artery disease, and 2) the interruption of beta-blocker therapy increases the risk of adverse cardiac events.

Adaptation mechanisms during myocardial ischemia in chronic unstable angina pectoris

Unstable angina with a clinical duration of < 2 months is characterized angiographically by a high incidence of complex lesions. Some patients have ischemic rest pain syndromes of longer duration. Thus, we retrospectively analyzed, in blinded fashion, the clinical and angiographic findings in 52 patients with unstable angina of < 2 months' duration (group A), and compared the results with those of 32 patients with unstable angina of > 6 months' duration (group B). Group B had a greater number of diseased vessels and better collateral circulation, but had fewer eccentric lesions. There were no differences in age, left ventricular function, or history of prior myocardial infarction. Thus, chronic unstable angina is associated with more extensive coronary disease than unstable angina of shorter duration. The role of different anatomic substrata and collateral circulation is discussed.

Elevation of the creatine kinase myocardial isoform following otherwise successful directional coronary atherectomy and stenting

Moderate elevation of creatine kinase (CK) MB isoform is common following otherwise successful percutaneous coronary revascularization, and is frequently interpreted as evidence of a non-Q-wave myocardial infarction. It is not clear, however, whether elevation of CK MB isoform carries sufficient adverse clinical impact to be categorized as a "major" complication. We therefore explored the incidence and clinical consequence of elevation of CK MB isoform in a consecutive series of 565 patients who had otherwise successful directional coronary atherectomy (n = 274) or stenting (n = 291), and were followed for a mean of 2 years. Of this cohort, 11.5% had postprocedure elevation of the CK MB isoform above normal (10 IU/liter). These patients tended to be older and to have undergone atherectomy of a de novo lesion with adverse morphology (thrombus, calcification, eccentricity). Patients with elevation of CK MB isoform following otherwise successful revascularization generally showed no adverse long-term sequelae (death, recurrent myocardial infarction, repeat revascularization) compared with patients without elevation of CK MB isoform. Only 2.3% of the patients who had CK MB isoform release > 50 IU/liter demonstrated a trend (p = 0.08) toward decreased late survival, compared with patients without CK MB isoform elevation. While minor CK MB isoform elevation is common (11.5%) after successful coronary stenting or directional atherectomy, it generally has no adverse clinical consequences, and should not be considered a major complication.(ABSTRACT TRUNCATED AT 250 WORDS)

A new look at coronary angiograms: plaque morphology as a help to diagnosis and to evaluate outcome

Characterization of plaque morphology can provide useful information beyond those generally yielded by the more traditional methods of interpretation of coronary angiograms based on assessment of severity of stenoses and number of diseased vessels. Focus on the culprit coronary lesion in acute myocardial infarction and in unstable angina allows recognition of the complex plaque and of presence of endoluminal thrombi that are closely associated to the mechanisms of the disease. Response to treatment in these clinical situations, and the healing process can be assessed by repeated opacifications of the lesion. The presence of a residual thrombus is associated with a worse clinical outcome and also a higher risk of complication if coronary angioplasty is performed. The prognostic information derived from the morphologic analysis extends to the chronic phase of the disease. The extent score of disease, defined as the sum of coronary artery segments showing a narrowing of any severity marks more severe disease and predicts future progression. Severity of stenosis is also a predictor. More severe lesions will occlude more frequently but most often without clinical consequences. Occlusion of less severe stenosis, on the other hand, leads to acute myocardial infarction or to the other manifestations of acute coronary syndromes. Other morphologic features are also associated with a higher risk of myocardial infarction. These include a geometry favoring blood flow separation and turbulence such as acute inflow and outflow angles of the stenosis and presence of a division within its vicinity. This new look at coronary angiograms may help orient therapy. Patients with angina and a significant stenosis will profit from a corrective intervention. Others with a high extent score should receive a comprehensive program for control of risk factors. Patients with a lesion of borderline significance at risk of activation should be closely monitored, and when clinical symptoms evolve, receive more intensive antithrombotic therapy. Quantification of the morphologic characteristics of the plaque, coupled to new techniques for endovascular imaging should lead in the future to better diagnostic and better risk stratification.

Long-term prognosis of medically treated patients with acute myocardial infarction and one-vessel coronary artery disease

Long-term prognosis was studied in 156 patients with acute myocardial infarction (AMI) with 1-vessel coronary artery disease (CAD). During a mean follow-up period of 110 months, 19 patients (14%) had reinfarction, 15 (9.6%) died (including 7 deaths of cardiac origin) and 15 (9.6%) were hospitalized for worsening of angina. A coronary arteriogram was obtained twice in 54 patients. The coronary arteriogram revealed multivessel CAD in all cases with reinfarction (n = 14). Ten percent of the patients with multivessel disease experienced a reinfarction during the initial 3 years after the onset of the first AMI. The recurrence rate of AMI in patients with 1-vessel disease increased gradually from the third year after the onset of their first AMI, reaching 10% in 6.7 years. The recurrence of AMI at the same region as the original infarction was detected in only 1 patient. Six of 19 patients (32%) with recurrence of AMI died and 13 survived after the reinfarction. It was difficult to predict future progression from the outcome of the comparison between the first and second coronary arteriograms. Thus, in patients with uncomplicated AMI with 1-vessel CAD, the prognosis is relatively good and the frequency of reinfarction is very low with conservative treatment.

First myocardial infarction in patients under 60 years old: the role of exercise tests and symptoms in deciding whom to catheterise

OBJECTIVE

To determine the role of exercise tests and assessment of angina in the detection of potentially threatening disease in young patients with infarcts.

DESIGN

Elective readmission of patients at a mean (SD) of 60 (30) days after acute myocardial infarction for assessment of angina, treadmill exercise tests, and cardiac catheterisation.

SETTING

Cardiology department of a teaching hospital.

PATIENTS

186 consecutive survivors, aged under 60 years and discharged from the coronary care unit after a first myocardial infarction.

MAIN OUTCOME MEASURES

Coronary arteriography, presence of angina, result of exercise tests, and referral for revascularisation.

RESULTS

31% of patients had either two vessel disease (with proximal left anterior descending involvement), three vessel disease, or left main stem disease. 49% of all patients had angina. Of the 173 patients who had an exercise test 34% had 1 mm and 24% had 2 mm of exercise induced ST depression. Thirty percent had no angina and a negative exercise test: after a mean (SD) follow up of 16 (4) months none of this symptom free sub-group had died, had experienced a further myocardial infarction, or had been referred for revascularisation. 79% of patients with either two vessel disease (with proximal left anterior descending involvement), three vessel disease, or left main stem disease had either angina or a 1 mm ST depression during the exercise test.

CONCLUSION

Patients without cardiac pain after myocardial infarction and without ST changes during an exercise do not need arteriography.

Independent and incremental prognostic value of exercise single-photon emission computed tomographic (SPECT) thallium imaging in coronary artery disease

OBJECTIVES

The objective of this study was to examine the independent and incremental prognostic value of exercise single-photon emission computed tomographic (SPECT) thallium imaging in patients with angiographically defined coronary artery disease.

BACKGROUND

Previous studies showed the importance of exercise thallium-201 in risk stratification. However, most of these studies used planar imaging techniques.

METHODS

Follow-up data were obtained in 316 medically treated patients with coronary artery disease. Cox proportional hazards regression models were used to examine the independent and incremental prognostic values of clinical, exercise, thallium and cardiac catheterization data.

RESULTS

There were 35 events (cardiac death or nonfatal myocardial infarction) at a mean follow-up time of 28 months. Univariate analysis showed that gender (chi-square = 5.1), exercise work load (chi-square = 3.1), extent of coronary artery disease and left ventricular ejection fraction (chi-square = 14.8) and thallium variables (chi-square = 22.7) were prognostically important. The thallium data provided incremental prognostic value to catheterization data (chi-square = 33.7, p < 0.01). The extent of the perfusion abnormality was the single best predictor of prognosis (chi-square = 14). Patients with a large perfusion abnormality had a worse prognosis than that of patients with a mild or no abnormality (Mantel-Cox statistics = 10.6, p < 0.001).

CONCLUSIONS

In medically treated patients with coronary artery disease, exercise SPECT thallium imaging provides independent and incremental prognostic information even when catheterization data are available. The extent of the perfusion abnormality is the single most important prognostic predictor.

Identification of extensive coronary artery disease in women by exercise single-photon emission computed tomographic (SPECT) thallium imaging

OBJECTIVES

The aim of this study was to examine the ability of exercise single-photon emission computed tomographic (SPECT) thallium imaging to identify high risk women with left main or three-vessel coronary artery disease using a stepwise discriminant analysis.

BACKGROUND

Previous studies have used statistical methods to identify high risk men with coronary artery disease. Only limited data are available in women.

METHODS

Exercise SPECT thallium imaging and coronary arteriography were performed for evaluation of chest pain in 243 women. Group 1 comprised 58 women with left main or three-vessel coronary disease and group 2 comprised 185 women with no or one- or two-vessel disease. Stepwise discriminant analysis was used to determine predictors of left main or three-vessel disease.

RESULTS

On univariate analysis, women in group 1 were older (p < 0.03) and had a lower exercise work load (p < 0.02), lower exercise heart rate (p < 0.004), higher prevalence rate of diabetes mellitus (p < 0.0003) and more multivessel thallium abnormality (p < 0.0001) compared with women in group 2. On multivariate analysis, only multivessel thallium abnormality (F = 43) and exercise heart rate (F = 6) were independent predictors of left main or three-vessel coronary disease. A model based on these two variables separated the women into three risk groups: 99 patients with 9%, 70 patients with 23% and 74 patients with 45% prevalence of left main or three-vessel disease (p < 0.0001).

CONCLUSIONS

High risk women with left main or three-vessel coronary disease can be identified by exercise SPECT thallium imaging.

Prognostic significance of progression of coronary atherosclerosis

BACKGROUND

Angiographic progression of coronary atherosclerosis is frequently observed in clinical practice and is used as an end point in clinical trials; however, its prognostic significance is unclear.

METHODS AND RESULTS

Progression defined as an increase in diameter stenosis by > or = 15% of at least one coronary lesion was seen in 141 (42%) of 335 patients who underwent repeat coronary arteriography after a 2-year interval as part of clinical trial. Coronary lesions were measured quantitatively from comparable end-diastolic frames selected by a radiologist viewing each pair of films together. During a mean follow-up of 44 +/- 10 months after the second arteriogram, cardiac death occurred in 19 patients (5.7%), cardiac death or nonfatal infarction was seen in 40 cases (11.9%), and 90 patients (26.9%) underwent coronary revascularization. At least one end point event occurred in 112 of the 335 patients. Sixteen of the 19 cardiac deaths were in progressors, a relative risk of 7.3 (95% CI, 2.2-24.7; p < 0.001). The relative risk of cardiac death or nonfatal infarction for progressors was 2.3 (1.3-4.2, p = 0.009) and of any cardiac event was 1.7 (1.3-2.3, p < 0.001). A stepwise multivariable Cox regression model of time to event was used to assess the relative contribution of progression as a predictor of coronary events. Low ejection fraction (p = 0.001), progression (p = 0.001), and hypertension (p = 0.011) were retained as predictors of cardiac death. Angina and the number of diseased vessels were the strongest predictors of revascularization.

CONCLUSIONS

Coronary progression is a strong, independent predictor of future coronary events, particularly cardiac death, and its use as a surrogate end point in clinical trials is justified.