Artery Stenosis In Coronary Angiography Research Articles

Association between 82Rb positron emission tomography-derived regional myocardial blood flow, severity of angiographic coronary artery stenosis, and mortality in patients with chest pain

Impairment in global myocardial flow reserve (MFR) on rubidium-82 (82Rb) positron emission tomography (PET) stress testing predicts cardiovascular events; however, the relationship between regional coronary artery territory myocardial blood flow (MBF) and invasive coronary angiography is unknown. In this study, patients with acute chest pain who were referred for coronary angiography after abnormal PET stress testing were evaluated. Both global and regional coronary territory stress and rest MBF were derived using 82Rb PET. Coronary artery stenosis severity was assessed using quantitative coronary angiography (QCA) performed within 3 months of PET. A total of 189 patients were followed for a median of 4.1 years. The results showed a weak correlation between regional MFR impairment (<1.7) and stenosis severity in the left descending artery (r = −0.20, P = 0.005), left circumflex artery (r = −0.15, P = 0.042), and right coronary artery (r = −0.26, P < 0.001). In addition, a weak correlation was observed between global MFR and stenosis in any vessel, in both binary and continuous analyses. However, impairment in MFR within any territory was associated with increased all-cause mortality in both unadjusted and adjusted analyses. In conclusion, this is the first large-scale study to examine the relationship between regional coronary territory MBF, coronary artery stenosis severity as assessed using QCA, and mortality. Although coronary territory MFR demonstrated a weak correlation with coronary stenosis severity, impairment in per-territory MFR was significantly associated with increased all-cause mortality, suggesting that mechanisms such as diffuse atherosclerosis and/or microvascular disease may be contributing factors.

Effects of α-lipoic acid therapy on sympathetic heart innervation in patients with previous experience of transient takotsubo cardiomyopathy

BackgroundTakotsubo syndrome is a stress cardiomyopathy, characterized by reversible left ventricle (LV) apical ballooning in the absence of significant angiographic coronary artery stenosis. The frequent association with emotional stress suggests in this disease an autonomic nervous system involvement. We could think that a therapeutic treatment targeting heart sympathetic dysfunction could be of crucial importance. MethodsFrom January 2010 to June 2012, 886 patients were consecutively evaluated at Cardarelli Hospital, Naples, Italy. Among these, 48 patients met takotsubo cardiomyopathy (TCM) criteria. Each patient was assessed with history and physical examination, 12-lead electrocardiogram, serum troponin, coronary arteriography, and left ventricular angiogram, perfusion myocardial scintigraphy with technetium 99m, with echocardiography and 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy. At discharge, the surviving patients were randomly assigned to α-lipoic acid (ALA) treatment (600mg once daily) or placebo. Following discharge, after the initial TCM event, patients returned to our outpatient clinic at Internal Medicine of the Second University Naples for the follow-up evaluation quarterly until 12 months. Routine analysis, myocardial damage serum markers, oxidative stress serum markers, pro-inflammatory cytokines, and sympathetic tone activity were evaluated in all patients. ResultsALA administration improved MIBG defect size at 12 months compared to placebo. ConclusionsAdrenergic cardiac innervation dysfunction in TCM patients persists after previous experience of transient stress-induced cardiac dysfunction. ALA treatment improves the adrenergic cardiac innervation. This study evaluates whether sympatho-vagal alterations are TCM event-related.

Osteoprotegerin gene polymorphism is not associated with angiographic coronary artery stenosis and calcification in Korean

Aim: Serum level of osteoprotegerin (OPG) has been suggested to be associated with osteoporosis, early coronary artery disease and coronary calcification. However, there was little data regarding the relation of the coronary artery disease and calcification with OPG gene mutation.

Effects of the topographical extent of coronary artery ectasia on coronary blood flow in patients with aortic aneurysms.

Aortic aneurysms are associated with coronary artery ectasia (CAE). However, the relation between the extent of CAE and coronary blood flow in patients with aortic aneurysms is not fully understood. This study was undertaken to assess the angiographic characteristics and effects of the topographical extent of CAE on coronary blood flow in patients with aortic aneurysms. This study consisted of 93 consecutive patients with aortic aneurysms (AA group) and 79 patients without aortic aneurysms who had angiographically normal coronary arteries as the control group (Control group). Coronary flow velocity was determined using the thrombolysis in myocardial infarction frame count (TFC) and the topographical extent of CAE was assessed. In the AA group, 43 patients (46.2 %) had significant coronary artery stenosis and 37 patients (40.2 %) had diffuse CAE. TFC was significantly higher in the AA group than in the control group in all 3 coronary arteries. Furthermore, mean corrected TFC (CTFC) was significantly higher in the AA group than in the control group (40.1 ± 10.7 vs. 25.8 ± 6.5, p < 0.001). In the AA group, mean CTFC in patients with diffuse CAE was significantly higher than that in patients with segmental CAE (50.2 ± 8.7 vs. 33.6 ± 5.2, p < 0.001). The mean CTFC correlated positively with the topographical extent of CAE. Many patients with aortic aneurysms were accompanied with angiographic coronary artery stenosis and CAE. Furthermore, patients with aortic aneurysms had higher CTFC than those without aortic aneurysms and it was primarily driven by more frequent prevalence of diffuse CAE.

Correlation between clinical prediction tests for coronary heart disease and findings on spect myocardial perfusion scintigraphy and coronary angiography

Predictive clinical tests are important diagnostic tools in determining groups of patients who should undergo further diagnostic methods for detection of coronary artery disease. The aim of this study was to determine the correlation between the probability of the existence of the coronary heart disease (CHD) obtained with Duke's clinical prediction tests for the existence of coronary artery disease and the results obtained by SPECT myocardial perfusion scintigraphy and coronary angiography. Patients and methods: The study included 56 patients with symptoms of angina pectoris (AP), 35 men and 21 women, aging 32-78 years. In all patients, the probability of the existence of coronary artery disease was calculated, i.e. the need for other diagnostic methods, by means of Duke clinical prediction (DCS). The patients subsequently underwent SPECT myocardial perfusion scintigraphy (SPECT MPI) with exercise stress test and with calculating Duke treadmill score (DTS), followed by coronary angiography (CA). The results were statistically analyzed using SPSS statistical tools, nonparametric statistical tests. Results: DCS showed a low CHD probability in 10 (17.9%), while in 46 (82.1%) there was moderate probability. DTS showed low probability in 8 (14.3%) and in 48 (85.7%) high probability of CHD. SPECT MPI resulted in 22 (39.3%) normal and 34 (60.7%) pathologilal states. CA was negative in 21 (37.5%), while in 35 (62.5%) showed significant coronary artery stenosis. In the group with low DCS and DTS probability for CHD there were no perfusion defects in SPECT MPI and no coronary artery stenosis in CA. Conclusion: Predictive clinical tests DCS and DTS, which confirm or reject suspicion of CHD, represent an important diagnostic tool that avoids unnecessary exposure of patients to further diagnostic methods which mean either an invasive diagnostic approach or any unnecessary exposure of patients to ionizing radiation. DCS and DTS have high negative predictive value and are reliable tools for selection of AP patients for further diagnostic modalities.

Acceleration Time of Systolic Coronary Flow Velocity to Diagnose Coronary Stenosis in Patients with Microvascular Dysfunction

The aim of this study was to test whether acceleration time of systolic coronary flow velocity could contribute to the diagnosis of coronary stenosis in patients with microvascular dysfunction, on the basis of the hypothesis that systolic coronary flow is less influenced by microvascular function because of compressed myocardium. Coronary flow velocity was assessed in the left anterior descending coronary artery during hyperemia with intravenous adenosine by echocardiography in 502 patients who were scheduled for coronary angiography because of coronary artery disease and significant valvular disease. Coronary flow velocity reserve (CFVR) and the percentage acceleration time (%AT), as the percentage of the time from the beginning to the peak of systolic coronary flow over systolic time during hyperemia, were calculated. The diagnostic ability of CFVR and %AT for angiographic coronary artery stenosis was then analyzed. As invasive substudies, fractional flow reserve and %AT by a dual-sensor (pressure and Doppler velocity) guidewire were measured simultaneously with %AT on transthoracic echocardiography (n= 14). Patients with coronary stenosis had significantly lower CFVR (1.7 ± 0.4) and greater %AT (65 ± 9%) compared with those without stenosis (2.6 ± 0.6 and 50 ± 13%, respectively). Percentage acceleration time by Doppler echocardiography was in good agreement with %AT (r= 0.98) and fractional flow reserve (r= 0.74) invasively measured by dual-sensor guidewire. Cutoff values of CFVR and %AT were determined as 2.0 and 60% in receiver operating characteristic curve analysis. The sensitivity, specificity, and accuracy of CFVR to detect coronary stenosis were 71.1%, 77.3%, and 75.4%, while those of %AT were 83.4%, 71.8%, and 75.4%, respectively. In addition, %AT provided high accuracy to detect coronary stenosis, especially in patients with previous myocardial infarctions, valvular disease, and left ventricular hypertrophy (81.1%, 84.1%, and 73.4%, respectively). The %AT of systolic coronary flow velocity is a promising marker to diagnose coronary stenosis in patients with microvascular dysfunction.

The Clinical Utility of Gene Expression Testing on the Diagnostic Evaluation of Patients Presenting to the Cardiologist With Symptoms of Suspected Obstructive Coronary Artery Disease

Accurate, noninvasive evaluation for obstructive coronary artery disease (CAD) remains challenging and inefficient. In this study, 171 patients presenting with stable chest pain and related symptoms without a history of CAD were referred to 6 cardiologists for evaluation. In the prospective cohort of 88 patients, the cardiologist's diagnostic strategy was evaluated before and after gene expression score (GES) testing. The GES is a validated, quantitative blood-based diagnostic test measuring peripheral blood cell expression levels of 23 genes to determine the likelihood of obstructive CAD (at least 1 vessel with ≥ 50% angiographic coronary artery stenosis). The objective of the study was to measure the effect of the GES on diagnostic testing using a pre/post study design. There were 83 prospective patients evaluable for study analysis, which included 57 (69%) women, mean age 53 ± 11 years, and mean GES 12.5 ± 9. Presenting symptoms were classified as typical angina, atypical angina, and noncardiac chest pain in 33%, 60%, and 7% of patients (n = 27, 50, and 6), respectively. After GES, changes in diagnostic testing occurred in 58% of patients (n = 48, P < 0.001). Of note, 91% (29/32) of patients with decreased testing had low GES (≤ 15), whereas 100% (16/16) of patients with increased testing had elevated GES (P < 0.001). A historical cohort of 83 patients, matched to the prospective cohort by clinical factors, had higher diagnostic test use compared with the post-GES prospective cohort (P < 0.001). In summary, the GES showed clinical utility in the evaluation of patients with suspected obstructive CAD presenting to the cardiologist's office.

OS104. Are preeclampsia and adverse obstetrical outcomes predictors for longterm cardiovascular disease?

Epidemiologic studies suggest that pregnancy complications such as preeclampsia, gestational diabetes, preterm delivery and low birth weight independently increase maternal risk for future development of cardiovascular disease. To further investigate whether preeclampsia, gestational diabetes, and adverse obstetrical outcomes such as placental abruption, intrauterine growth restriction and preterm delivery, are independent risk factors for longterm cardiovascular disease. This was a case-control study where 252 parous women (cases) with coronary artery disease were matched with a parous woman within 5 years of age with no known coronary artery disease (controls). Participants were recruited from the Royal Alexandra Hospital in cardiac catheterization lab recovery room in Edmonton, Canada. Women with significant angiographic coronary artery stenosis were eligible as cases and those without were eligible as controls. Participants were interviewed on their pregnancy histories and traditional cardiovascular risk factors, such as hypertension, diabetes etc. Descriptive statistics, chi-square tests and conditional regression analysis were performed. We recruited 244 cases and 246 controls. The average age was 66.3 and 65.8 respectively. Cases were more likely obese, had more pregnancies as well as traditional cardiovascular risk factors than controls. Adverse pregnancy outcomes were similar between the two groups except gestational hypertension. However, it was not statistically significant in the conditional logistic regression model. Independent risk factors for future cardiovascular diseases were: dyslipidemia (OR 12.8), hypertension (3.0), and being a current (OR 7.4) or former smoker (1.8). Adverse pregnancy outcomes In this study, adverse pregnancy outcomes were not independently associated with cardiovascular disorders. Our study was limited by recall bias, and ascertainment of diagnosis.Our study supports that dyslipidemia, hypertensiion and smoking increase future cardiovascular disease. Further studies are needed to examine a postpartum intervention model to proactively manage cardiovascular risk factors, such as lipids, in these at-risk women.

Osteoprotegerin gene polymorphism is not associated with angiographic coronary artery stenosis and calcification in Koreans

Objective: Serum level of osteoprotegerin (OPG) has been suggested to be associated with osteoporosis, early coronary artery disease and coronary calcification. However, there was little data regarding the relation of the coronary artery disease and calcification with OPG gene mutation. Methods and results: Four hundred and thirty four patients referred for coronary angiography due to their chest pain were enrolled. All the patients have undergone coronary angiography and were investigated for their genetic mutations with regard to four genes: A163G, G209A, T245G, T950C of OPG gene.

Intraoperative Left Ventricular Apical Ballooning: Transient Takotsubo Cardiomyopathy During Orthotopic Liver Transplantation

TRANSIENT LEFT VENTRICULAR (LV) apical ballooning, also referred to as “takotsubo syndrome,” is a stress-induced, reversible cardiomyopathy. The syndrome is characterized by transient LV apical and midsystolic dysfunction with basal hyperkinesis. The affected heart, when viewed by echocardiography or catheterization, mimics a shape described as a round-bottomed narrow-necked Japanese fishing pot used to trap octopus, which in Japanese is called “takotsubo.” 1 Bybee K.A. Kara T. Prasad A. et al. Systematic review: Transient left ventricular apical ballooning: A syndrome that mimics ST-segment elevation myocardial infarction. Ann Intern Med. 2004; 141: 858-865 Crossref PubMed Scopus (1218) Google Scholar The takotsubo syndrome was first described in the Japanese literature in 1990 and has since been characterized by transient LV apical ballooning in the absence of significant angiographic coronary artery stenosis and cardiomyopathy. 1 Bybee K.A. Kara T. Prasad A. et al. Systematic review: Transient left ventricular apical ballooning: A syndrome that mimics ST-segment elevation myocardial infarction. Ann Intern Med. 2004; 141: 858-865 Crossref PubMed Scopus (1218) Google Scholar , 2 Dote K. Sato H. Tateishi H. et al. Myocardial stunning due to simultaneous multivessel coronary spasms: A review of 5 cases. J Cardiol. 1991; 21: 203-214 PubMed Google Scholar In this article, the first case of takotsubo cardiomyopathy under general anesthesia in the United States is reported. 1 Bybee K.A. Kara T. Prasad A. et al. Systematic review: Transient left ventricular apical ballooning: A syndrome that mimics ST-segment elevation myocardial infarction. Ann Intern Med. 2004; 141: 858-865 Crossref PubMed Scopus (1218) Google Scholar , 3 Takigawa T. Tokioka H. Chikai T. et al. A case of undiagnosed “takotsubo” cardiomyopathy during anesthesia. Masui. 2003; 52: 1104-1106 PubMed Google Scholar , 4 Jabaudon M. Bonnin M. Bolandard F. et al. Takotsubo syndrome during induction of general anesthesia. Anaesthesia. 2007; 62: 519-523 Crossref PubMed Scopus (45) Google Scholar , 5 Ramakrishna G. Ravi B.S. Chandrasekaran K. Apical ballooning syndrome in a postoperative patient with normal microvascular perfusion by myocardial contrast echocardiography. Echocardiography. 2005; 22: 606-610 Crossref PubMed Scopus (25) Google Scholar , 6 Gavish D. Rozenman Y. Hafner R. et al. Takotsubo cardiomyopathy after general anesthesia for eye surgery. Anesthesiology. 2006; 105: 621-623 Crossref PubMed Scopus (40) Google Scholar This case report describes the intraoperative and postoperative events leading to the diagnosis of takotsubo cardiomyopathy. In addition, the diagnostic criteria and therapeutic modalities in the management of this acutely life-threatening cardiomyopathy are outlined. Takotsubo Cardiomyopathy in a Liver Transplant Recipient: A Diagnosis of Exclusion?Journal of Cardiothoracic and Vascular AnesthesiaVol. 23Issue 2PreviewTiwari and D'Attellis1 recently reported on transient takotsubo cardiomyopathy (TCM) during liver transplantation (LT). This was only the second case of this type of ventricular dysfunction ever reported in a LT recipient. The first such reported complication occurred several hours after LT.2 In 1 case, major complications triggered the event and in the other it developed spontaneously. In both cases, myocardial infarction was assumed; both patients underwent coronary arterial angiography, which excluded coronary artery disease as a cause in both cases. Full-Text PDF

The Association between Coronary Artery Calcification on MDCT and Angiographic Coronary Artery Stenosis

Background and Objectives:The assessment of CT-derived coronary artery calcification (CAC) has been used as a surrogate measurement for coronary atherosclerosis. However, the blooming artifact caused by CAC on MDCT is the potential limitation when evaluating the coronary artery stenosis. The aim of this study was to classify the morphologic characteristics of CAC on MDCT and to test whether this new classification predicts the stenotic severity on coronary angiography. Subjects and Methods:A total of 73 CAC lesions were observed on 64 slice MDCT in the 56 enrolled patients (M:F=33:23, mean age: 66±9.3 years) who underwent coronary angiography. The morphologic types of CAC on 64-slice MDCT were classified into four groups [degree of stenosis (S), shape of the calcification (M), length of the calcification (L) and the number of calcified vessels (N)] with using a scoring system, and this morphologic classification was compared with the angiographic severity of coronary stenosis. Result: Diffuse (L3), elongated (M2) and multi-vessel (N2) calcified lesions were significantly associated with angiographic coronary artery stenosis (p=0.03, p=0.019 and p=0.002, respectively) On the multivariate regression analysis, multivessel CAC was the only independent predictor for significant coronary artery stenosis [p=0.019, β=3.77, CI: 1.23-11.5 (95%)]. The type of stenosis (luminal narrowing ≥50%) accompanying CAC on MDCT was not correlated with the angiographically determined stenosis (p=0.13). A total morphologic score less than 4 had a negative predictive value of 78% for predicting significant coronary artery stenosis. Conclusion:Our results suggest that the diffuse and multi-vessel CAC on MDCT can predict the coronary artery stenosis; however, the stenosis severity of the lesion accompanying CAC on MDCT might not coincide with the angiographic severity. Therefore, the morphologic classification with this scoring system should be considered for use when evaluating lesion with CAC on MDCT. (Korean Circulation J 2007;37:167-172)

The relationship between hepatitis b virus surface antigen and angiographic coronary artery stenosis in Chinese

The relationship between hepatitis b virus surface antigen and angiographic coronary artery stenosis in Chinese

Association of blunted nighttime blood pressure dipping with coronary artery stenosis in men

The aim of this work was to study the association between blunted nighttime dipping of blood pressure (BP) and coronary artery stenosis in men. Sixty-eight men (aged 52 +/- 11 years) with coronary artery disease (CAD) defined as >/=70% diameter stenosis, and a control group of 68 men, matched for age and risk factors without angiographic CAD were studied by ambulatory blood pressure monitoring. Patients were defined as nondippers when the nighttime systolic and diastolic BP decrease was <10%. Medications included beta-blockers in 20 (15%), calcium antagonists in 39 (29%), angiotensin-converting enzyme inhibitors in 44 (32%), angiotensin receptor blockers in 21 (15%), and diuretics in 37 (27%) patients. A logistic regression model was used to define independent predictors of angiographic CAD. Covariates were symptoms, total cholesterol, daytime BP, and nondipping. A larger proportion of patients with CAD were nondippers as compared to control subjects (49 [72%] v 31 [46%], P < .005). In a logistic regression model, nondipping was associated with coronary artery stenosis independent of other clinical parameters (odds ratio 3.6, 95% confidence interval 1.6-8.8). Blunted nighttime dipping of BP is independently associated with angiographic coronary artery stenosis in men.

Accuracy of 99mTc-tetrofosmin myocardial tomography in the evaluation of coronary artery disease

Background. Technetium 99m-labeled myocardial agents have been proposed as an alternative to thallium 201. The aim of this study was to assess retrospectively the accuracy of exercise myocardial 99mTc-tetrofosmin scintigraphy with tomographic imaging (SPECT) in a large group population in the evaluation of coronary artery disease. Furthermore we evaluated the relation between the severity of scintigraphic impaired myocardial perfusion and the angiographic coronary artery stenoses in patients without myocardial infarction and with stenosis localized exclusively in the proximal segment of the 3 main coronary arteries. Methods and Results. The study group consisted of 235 consecutive patients, 204 (87%) of whom were men, with a mean age of 57 ± 10 years, and with suspected or known coronary artery disease, who underwent 99mTc-tetrofosmin SPECT and coronary angiography. Furthermore, 61 patients in a low-likelihood group for coronary artery disease were also studied. Significant disease was defined by ≥50% luminal coronary artery stenosis in ≥1 native coronary artery or major branch or in a saphenous vein graft or arterial mammary graft. The overall sensitivity was 95%, specificity was 76%, and predictive accuracy was 95%. The normalcy rate for the low-likelihood group was 93%. Sensitivity was 71% for the left anterior descending artery, 61% for the left circumflex artery, and 73% for the right coronary artery. Specificity was 94% for the left anterior descending artery, 96% for the left circumflex artery, and 91% for the right coronary artery. Predictive accuracy was 79% for the left anterior descending artery, 78% for the left circumflex artery, and 81% for the right coronary artery. In patients without myocardial infarction linear regression analysis between scintigraphy and angiography showed a significant correlation in patients with severe proximal coronary artery stenosis ( r = 0.53, P < .002), but not in those with moderate proximal stenosis ( r = 0.31, P = NS). Conclusions. This study shows that 99mTc-tetrofosmin SPECT is accurate in the detection of coronary artery disease. The relation of the severity of scintigraphic impaired myocardial perfusion and angiographic coronary artery stenosis, however, may differ significantly in patients with proximal stenosis of different severity.

ECG Diagnosis of Coronary Artery Disease

Objective: In order to assess the diagnostic accuracy of ST depression in the diagnosis of coronary artery disease (CAD) in patients with suspected myocardial ischemia we compared ST depression in 3‐lead ambulatory ECG (AECG) with that of exercise tolerance testing (ETT).Methods: Significant coronary artery stenosis in coronary angiography was used as a standard reference. ST analysis could be performed in 106 of the investigated 113 patients, all with suspected CAD. One person with left bundle branch block was excluded from the ST analysis, and six persons could not perform ETT.Results: Seventy‐eight of the 106 patients had at least one significant stenosis (&gt; 70% narrowing) and 28 had no stenosis according to coronary angiography. The sensitivity for AECG was 62% and for ETT it was 63%, the specificity for AECG was 79% and for ETT the specificity was 57%. The accuracy for AECG was 66%, and for ETT it was 61%. We also evaluated late potentials (LPs) from the AECG tapes in order to correlate LP to left ventricular function (LVF), myocardial infarction (Ml), and/or CAD. We found that LP correlates better to advanced CAD than to Ml or LVF.Conclusion: The accuracy of ST diagnosis of CAD in patients with suspected myocardial ischemia using AECG was equal to that of a maximal ETT. LP finding from an AECG tape may support the argument for CAD in patients with ST depressions at AECG.

Detection of Silent Myocardial Ischemia During Ambulatory Monitoring by Time‐Frequency Power Spectral Analysis

Background: The nonstationary conditions of unrestricted ambulatory ECG monitoring preclude any meaningful detection of short‐term transient events by conventional time series methods. Time‐frequency analysis offers a unique approach that tracks the frequency content of the signal as it is changing in time.Methods: We compared the ability of three methods: time‐frequency, RR interval time series, and global HR power spectra to detect the occurrence of silent ischemia (ST depression &gt; 1.5 mm × 80 ms for at least 2 min) among 17 Holter records. The records were obtained from five patients (age 52 ± 2 years) with angiographic coronary artery stenosis &gt; 70%. Individual segments were analyzed in a blinded fashion by three of the authors (MK, EF, AM).Results: Neither changes in the RR interval series nor sequential 2.2‐minute power spectra was significantly predictive of ischemia. Conversely, an abrupt loss of variance in the time‐frequency plot was associated with ST depression 82.3% of the time (Chi square = 3.41; P &lt; 0.055). There was a weaker correspondance between the duration of ST depression and loss of autospectral power.Conclusions: Although a significant correlation (r2= 0.863) was seen between the maximum low frequency power (sympathetic modulation) and sudden decreases in RR interval, there were at least three instances where no detectable change in HR occurred during episodes of ischemia. These preliminary observations offer hope that time‐frequency methods may prove useful in the detection of transient events in the ambulatory ECC record.

Relation between coronary artery stenosis assessed by visual, caliper, and computer methods and exercise capacity in patients with single-vessel coronary artery disease. The Veterans Affairs ACME Investigators.

Practitioners often assume a close relation between angiographic coronary artery stenosis and patient functional capacity. To test this unproven hypothesis, we analyzed the relation between coronary artery stenosis measured by different methods and maximal treadmill exercise tolerance in patients with single-vessel disease before and after intervention by percutaneous transluminal coronary angioplasty (PTCA). Coronary angiography and maximal exercise testing off anti-ischemic medication were performed before random assignment of 227 patients with single-vessel coronary artery disease to PTCA or drug therapy. Six months later, angiography and exercise testing were repeated with patients assigned to PTCA off anti-ischemic therapy so that the altered coronary stenosis was the only consistent variable. Patients assigned to drug therapy were exercised on drug therapy. Coronary stenosis was assessed visually by the local investigator and quantitatively by blinded caliper and computer methods in central laboratories. Variabilities of caliper and computer measurements were established in a subset read twice. Visually estimated stenosis > or = 90% at baseline was associated with shorter exercise duration (7.9 versus 9.2 minutes, P < .04). Similar segregation at baseline was not observed with caliper or computer methods. Regardless of the method of measurement used, correlation between changes of lesion severity and exercise duration from baseline to follow-up was poor. Patients were angiographically classified as "better," "unchanged," or "worse" if follow-up stenosis was below, within, or above 2 SD of mean technical variability from baseline (+/- 18.8%, caliper, +/- 14.6%, computer). Exercise duration for PTCA patients improved among those with better lesions (+2.4 minutes, n = 50, P = .001) but also among those with unchanged lesions (+1.9 minutes, n = 41, P < or = .001). Unchanged medically treated patients improved less (+0.5 minutes, n = 86, P = .04). Results were similar when patients were angiographically classified by minimum lumen diameter. Handheld calipers and quantitative coronary angiography are equivalent techniques for making anatomic measurements. Neither method identified patients having reduced exercise capacity at baseline as well as visual estimation. The relation between changes of coronary stenosis and exercise duration is highly variable, at least in part because of the insensitivity of angiographic methods for detecting small but potentially important changes. Minimal anatomic improvement 6 months after PTCA does not preclude a good functional outcome. Contrary to common belief, angiographic stenosis does not correlate well with functional capacity, even in patients with single-vessel disease.

Abnormal nondetect zone myocardial thallium washout ratio in patients with reversible thallium defects and normal coronary arteriograms

Thallium myocardial defects in patients with no angiographic coronary artery stenosis have been attributed to attenuation effects and other artifacts. Of 323 patients having thallium myocardial imaging following dipyridamole infusion, 10 of 159 patients with a segmental perfusion abnormality were found to have no luminal diameter stenosis >20% on coronary angiography and no electrocardiographic (ECG) evidence of myocardial infarction or left bundle branch block. A time-standardized regional thallium washout ratio was calculated as thallium myocardial counts with dipyridamole to counts without dipyridamole. In comparison to 10 age-matched control patients with no evidence of cardiac disease and no myocardial thallium defect, study patients had a lower regional myocardial thallium washout ratio from both the defect and nondefect (1.57 ± 0.40 versus 2.27 ± 0.92, p = 0.041) zones. Nine of the 10 study patients had independent evidence of noncoronary heart disease, including echocardiographic or ECG evidence of left ventricular hypertrophy in six patients. In patients with thallium defects and normal coronary arteriograms, a time-standardized regional thallium myocardial washout ratio for the nondefect zone may aid in the differentiation of patients with noncoronary heart disease from those with soft tissue artifacts.