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PubMed1984

[Nature of the coronary vessel response to increased myocardial contractile function].

Correlation between performance of the myocardium and its blood supply was studied in the dog isolated heart. Accommodation of coronary circulation to changes in myocardiac needs had a complex nature: increasing of cardiac performance within physiological range was accompanied by active changes in coronary resistance, the latter resulting in an increase of the blood flow. A more obvious hyperemic response to transient ischemia in these conditions was attributed to raising of the coronary vessels reactivity. Volume overloading of the heart resulted in lowering of its blood supply and actualization of coronary dilating reserve combined with lowering reactivity of the coronary vessels and with changes in passive component of the coronary resistance due to increasing myocardiac diastolic strain.

Adaptation, Physiological↗
PubMed1987

[Angioplasty of internal mammary artery and saphenous vein bypasses and native coronary vessels in a patient with rapidly progressing disease].

Although coronary artery bypass is an effective treatment for patients with coronary artery disease, early graft failure is sometimes observed. We report here on a patient who had triple-vessel coronary bypass surgery, and 3 subsequent coronary angioplasty procedures of grafts and native vessels in the 13 following months, because of recurrence of angina. Each procedure was followed by disappearance of signs and symptoms of myocardial ischemia. This case illustrates the complementary approach of coronary artery bypass surgery and percutaneous angioplasty to myocardial revascularization in patients with rapidly progressive coronary disease.

Angina Pectoris↗
PubMed2003

[Long-term prognosis in patients with single-vessel or double-vessel coronary artery disease: does successful revascularization achieved by coronary angioplasty improve late outcome?].

OBJECTIVES: It is not clear whether revascularization by coronary angioplasty improves long-term prognosis in patients with stable angina, single- or double-vessel coronary artery disease. This study investigated the extent of late revascularization achieved by percutaneous transluminal coronary angioplasty(PTCA) and evaluated the long-term effect of revascularization in patients with coronary artery disease. METHODS: This study reviewed 178 patients with single-vessel or double-vessel disease and significant coronary diameter stenosis(American Heart Association classification, 75% or more stenosis), but excluded 35 patients with failed revascularization of the target vessels because of initial failed angioplasty(n = 14) or restenosis(n = 21). The remaining 143 patients were available for assessment. Revascularization was successful at follow-up angiography after the last angioplasty in 105 patients(Group A). The remaining 38 patients received conservative medical therapy(Group B). Kaplan-Meier survival curves were used to examine absolute survival difference. RESULTS: One hundred forty-three patients(mean age 64 +/- 9 years) were followed-up for 3.8 +/- 1 years. The patients were 70.6% male, 59.4% had myocardial infarction and 76.9% had single-vessel disease. Anatomical complete revascularization in the chronic phase was accomplished in 80 patients with single-vessel disease(97.6%) and 11 patients with double-vessel disease(47.8%). The event-free survival rate was not significantly different between Group A and Group B(88.6% vs 84.2%, p = NS). Cardiac survival rate decreased significantly in Group B compared to Group A(89.5% vs 99.0%, p < 0.01). This difference in survival rate was due to sudden cardiac death in Group B(7.9% vs 0%, p < 0.05). Non-fatal myocardial infarctions occurred in seven patients(6.7%) with revascularization and in one patient(2.6%) with conservative medical therapy, but with no significant difference. Late successful revascularization improved cardiac survival rate in patients with proximal left anterior descending coronary artery involvement or single-vessel disease. CONCLUSIONS: Cardiac events decreased and long-term prognosis appeared to be a good possibility in patients with single- or double-vessel coronary artery disease if late successful revascularization of target vessel was accomplished.

Aged↗
PubMed1980

Selective blockade of neurotensin-induced coronary vessel constriction in perfused rat hearts by a neurotensin analogue.

[D-Trp11]-NT, an analogue of neurotensin (NT) in which Tyr11 was replaced with D-Trp, was found to antagonize selectively NT-induced coronary vessel constriction in perfused rat hearts, in concentrations varying between 1.3 x 10(-7) and 1.1 x 10(-6) M. Higher concentrations of [D-Trp11]-NT displayed NT-like activity. In rat stomach strips and guinea pig atria, [D-Trp11]-NT exhibits full intrinsic activity, markedly reduced affinity for NT receptors, but no inhibitory effect against NT. These results suggest that the receptors mediating the constrictor action of NT in the coronary vessels of rat hearts are pharmacologically distinct from those subserving the stimulant effects of NT in rat stomach strips and guinea pig atria.

Animals↗
PubMed1992

Absence of severe exercise-induced ischemia does not identify low-risk patients with three-vessel coronary artery disease.

The purpose of this study was to determine the prognosis of medically treated patients with three-vessel coronary artery disease and normal left ventricular function who do not have severe ischemia on exercise radionuclide angiography. The absence of severe ischemia was defined prospectively (in accordance with previously published criteria) as the presence of at least one of the following: (1) workload more than 600 kg-m/min, (2) ST-segment depression of less than 1 mm, or (3) unchanged or increased left ventricular ejection fraction during exercise. Of 42 patients (33% in functional class III or IV) followed up for a median duration of 53 months (range, 1 to 84 months), 22 had initial cardiac events during follow-up, including 6 cardiac deaths, 5 nonfatal myocardial infarctions, and 11 late (a median of 29 months after the exercise study) coronary revascularization procedures. At 4 years of follow-up, the overall survival was 83%. Survival free of cardiac death or myocardial infarction was 77%, and survival free of all cardiac events was 59%. Even in the absence of severe exercise-induced ischemia, medically treated patients with three-vessel coronary artery disease and normal left ventricular function still have a poor long-term outcome.

Coronary Disease↗
PubMed2002

Triple vessel stenting for triple vessel coronary disease.

BACKGROUND: Randomized clinical trials have established the feasibility of implanting multiple coronary stents and, in selected patients, have measured survival after multiple stenting to be comparable to coronary artery bypass graft surgery (CABG). However, the proportion of candidates for this therapy is unclear. this prospective study was performed to measure the percentage of patients eligible for elective multiple stenting of triple vessel coronary artery disease and to examine their short- and intermediate-term outcomes. METHODS: Between January 1996 and January 1999, percutaneous coronary interventions (PCI) were performed in 6,810 consecutive patients, of whom 115 (1.7%) had triple vessel coronary artery disease treated with > or =3 stents. The mean age of these patients was 62.9 years (range, 35-85 years), 83% were men and 13 patients (11%) were diabetic. The treatment was performed in a single procedure in 80% of patients and 362 vessels were dilated, including the left anterior descending artery in 85%, the right coronary artery in 84%, the left circumflex in 49%, the left diagonal artery in 27%, the posterior descending artery in 8% and the posterior lateral artery in 4% of patients. RESULTS: A total of 483 stents were implanted, representing an average of 4.2 +/- 1.4 stents per patients (range, 3-10 stents). The total length of stents averaged 66.9 +/- 4.9 mm. In-hospital adverse events included 2 deaths (1.7%), 2 emergency CABG (1.7%) and 5 myocardial infarctions (4.3%). The mean hospitalization duration was 2.7 +/- 2.2 days. During a follow-up ranging between 1 and 36 months (mean, 16.7 months), 2 patients died (1.7%), 2 patients underwent CABG (1.7%) and 22 patients (19.1%) underwent further coronary artery dilatations. The 3-year event-free survival was 71.3%. In univariate analysis, patients who underwent additional target vessel revascularization were younger and were more likely to have stented segments > 80 mm in the index procedure. No other clinical, angiographic or procedural characteristic was predictive of adverse events. CONCLUSIONS: In this consecutive series of patients undergoing elective PCI, candidates for stenting of > or =3 arteries were few. Most eligible patients underwent uncomplicated and immediately successful procedures. The long-term outcome was comparable to controlled studies of CABG, except for a higher rate of repeat revascularization procedures due to restenosis.

Age Factors↗
PubMed1980

The value of exercise electrocardiography and exercise thallium-201 myocardial perfusion scanning in determining the presence of single vessel coronary artery obstruction.

In 39 patients with single vessel coronary artery disease and no previous myocardial infarction, exercise thallium-201 myocardial perfusion scanning and 12 lead exercise electrocardiography (ECG) were compared to see how reliably each method identified the site of coronary artery obstruction. Significant (greater than or equal to 70% diameter) stenosis was present in the left anterior descending (LAD) coronary artery in 21 patients, in the right coronary artery (RCA) in 14 patients and in the left circumflex (LCX) in four patients. Thallium defects on the scan in the septal (SEPT), anteroseptal (ANT SEPT) and anterior (ANT) segments correlated (P less than 0 . 0005) with LAD disease and defects in the inferior (INF), posteroinferior (POST INF), and posterior (POST) segments correlated (P less than 0 . 0005) with RCA or LCX disease. Exercise induced ST segment elevation in VI and/or AVL correlated with LAD disease. The site of ischaemic ST depression did not correlate with disease in any vessel. ST segment depression in leads L2, 3, AVF (67%) and in leads V4--6 (67%) was most sensitive for detecting patients with LAD disease and ST depression in leads V4--6 was most sensitive (56%) for detecting patients with RCA or LCX disease but neither differentiated LAD from RCA/LCX disease.

Adult↗
PubMed2005

Reproducibility of 3D free-breathing magnetic resonance coronary vessel wall imaging.

AIMS: Although the coronary artery vessel wall can be imaged non-invasively using magnetic resonance imaging (MRI), the in vivo reproducibility of wall thickness measures has not been previously investigated. Using a refined magnetization preparation scheme, we sought to assess the reproducibility of three-dimensional (3D) free-breathing black-blood coronary MRI in vivo. METHODS AND RESULTS: MRI vessel wall scans parallel to the right coronary artery (RCA) were obtained in 18 healthy individuals (age range 25-43, six women), with no known history of coronary artery disease, using a 3D dual-inversion navigator-gated black-blood spiral imaging sequence. Vessel wall scans were repeated 1 month later in eight subjects. The visible vessel wall segment and the wall thickness were quantitatively assessed using a semi-automatic tool and the intra-observer, inter-observer, and inter-scan reproducibilities were determined. The average imaged length of the RCA vessel wall was 44.5+/-7 mm. The average wall thickness was 1.6+/-0.2 mm. There was a highly significant intra-observer (r=0.97), inter-observer (r=0.94), and inter-scan (r=0.90) correlation for wall thickness (all P<0.001). There was also a significant agreement for intra-observer, inter-observer, and inter-scan measurements on Bland-Altman analysis. The intra-class correlation coefficients for intra-observer (r=0.97), inter-observer (r=0.92), and inter-scan (r=0.86) analyses were also excellent. CONCLUSION: The use of black-blood free-breathing 3D MRI in conjunction with semi-automated analysis software allows for reproducible measurements of right coronary arterial vessel-wall thickness. This technique may be well-suited for non-invasive longitudinal studies of coronary atherosclerosis.

Adult↗
PubMed2005

Artifact-free coronary magnetic resonance angiography and coronary vessel wall imaging in the presence of a new, metallic, coronary magnetic resonance imaging stent.

BACKGROUND: Coronary in-stent restenosis cannot be directly assessed by magnetic resonance angiography (MRA) because of the local signal void of currently used stainless steel stents. The aim of this study was to investigate the potential of a new, dedicated, coronary MR imaging (MRI) stent for artifact-free, coronary MRA and in-stent lumen and vessel wall visualization. METHODS AND RESULTS: Fifteen prototype stents were deployed in coronary arteries of 15 healthy swine and investigated with a double-oblique, navigator-gated, free-breathing, T2-prepared, 3D cartesian gradient-echo sequence; a T2-prepared, 3D spiral gradient-echo sequence; and a T2-prepared, 3D steady-state, free-precession coronary MRA sequence. Furthermore, black-blood vessel wall imaging by a dual-inversion-recovery, turbo spin-echo sequence was performed. Artifacts of the stented vessel segment and signal intensities of the coronary vessel lumen inside and outside the stent were assessed. With all investigated sequences, the vessel lumen and wall could be visualized without artifacts, including the stented vessel segment. No signal intensity alterations inside the stent when compared with the vessel lumen outside the stent were found. CONCLUSIONS: The new, coronary MRI stent allows for completely artifact-free coronary MRA and vessel wall imaging.

Animals↗
PubMed2000

Magnetic resonance imaging of regional myocardial perfusion in patients with single-vessel coronary artery disease: quantitative comparison with (201)Thallium-SPECT and coronary angiography.

The clinical value of magnetic resonance perfusion imaging (MRI) was investigated by quantitative comparison with (201)thallium-single-photon emission computed tomography ((201)TI-SPECT) and quantitative coronary angiography (QCA). Short-axis imaging was performed during dipyridamole administration in 13 patients with single-vessel coronary artery disease. Using inner and outer contours, the myocardium was divided into 30 contiguous, radial regions. Defining a perfusion defect as a region with less than 90% of maximum (201)TI intensity, nine patients had a matching perfusion defect, two had no defect on both (201)TI-SPECT or MRI, and one had a defect on (201)TI-SPECT but not on MRI. One patient had a defect on both modalities but with inaccurate localization. Three perfusion parameters were investigated: a) maximum contrast enhancement (MCE); b) slope of the signal intensity versus time curve; and c) inverse mean transit time (1/MTT). The sensitivity and specificity of MCE in the detection of perfusion abnormalities with TI-SPECT as the reference method were 71% and 71%, respectively (slope 77% and 61%, 1/MTT 44% and 70%). Furthermore, correlations were calculated per patient for the entire circumference of the short-axis myocardium. Median correlations were as follows: MCE 0.92, slope 0.91, and 1/MTT 0.40. Mismatches between (201)TI defects and defects on MRI resulted in low mean correlations (MCE 0.45, slope 0.46, and 1/MTT 0.26). There was a trend between severity of perfusion defects on MRI (using MCE) and QCA stenosis area (r = -0.56, P = 0.06). Thus, MRI and (201)TI-SPECT demonstrate fair agreement in the assessment of perfusion defects but show moderate correlation when the entire short-axis myocardium is correlated.

Aged↗
PubMed1991

Effect of intracoronary serotonin on coronary vessels in patients with stable angina and patients with variant angina.

BACKGROUND: Serotonin, a major product of platelet activation, has potent vasoactive effects in animal models, but its role in human coronary artery disease remains largely speculative. METHODS: Using quantitative coronary angiography, we compared the effects of the intracoronary infusion of graded concentrations of serotonin (10(-7) to 10(-4) mol per liter) on coronary vessels in two groups of patients with different clinical presentations of coronary disease (nine with stable angina and five with variant angina), with the effects in a control group of eight subjects with normal vessels on angiography. RESULTS: Normal coronary vessels had a biphasic response to intracoronary serotonin: dilation at concentrations up to 10(-5) mol per liter, but constriction at 10(-4) mol per liter. Vessels in patients with stable angina constricted at all concentrations, with mean (+/- SEM) maximal decreases in diameter of 23.9 +/- 3.6, 33.1 +/- 3.9, and 41.7 +/- 3.1 percent from base line in proximal, middle, and distal segments at a serotonin concentration of 10(-4) mol per liter. Smooth segments constricted more than irregular segments (42.0 +/- 4.6 vs. 21.1 +/- 1.6 percent). Four patients with stable angina had a marked reduction in collateral filling. All the patients with stable angina had angina during the intracoronary infusion of serotonin, and electrocardiographic changes were noted in six. All the patients with variant angina had angina, electrocardiographic changes, and localized occlusive epicardial coronary-artery spasm at concentrations of 10(-6) (n = 2) or 10(-5) (n = 3) mol per liter. CONCLUSIONS: Patients with stable coronary disease do not have the normal vasodilator response to intracoronary serotonin, but rather have progressive constriction, which is particularly intense in small distal and collateral vessels. Patients with variant angina have occlusive coronary-artery spasm at a dose that dilates normal vessels and causes only slight constriction in vessels from patients with stable angina. These findings suggest that serotonin, released after the intracoronary activation of platelets, may contribute to or cause myocardial ischemia in patients with coronary artery disease.

Adult↗
PubMed1996

Can Tl-201 myocardial SPECT abnormalities in orthotopic heart recipients be explained by coronary vessel wall alterations assessed by intravascular ultrasound?

UNLABELLED: The aim of this study was to compare findings on coronary intravascular ultrasound and thallium-201 SPECT in patients following orthotopic heart transplantation. BACKGROUND: No data are available on whether pathological thallium scintigraphic findings in heart recipients are based on coronary vessel wall alterations identifiable by intravascular ultrasound. METHODS: 29 patients (mean age: 50.9 +/- 11.5 years; male n = 23) were investigated by means of intravascular ultrasound of selected coronary segments and thallium-201 myocardial SPECT. Patients were investigated 11.6 +/- 5.4 weeks post transplantation, a subgroup of 13 patients was re-investigated 70.2 +/- 18.4 weeks following transplantation. A total of 214 cross-sectional areas of the left coronary artery were examined using a 3.5 French intravascular ultrasound catheter to measure intimal index and the circumferential extension of a three-layer appearance of the vessel wall. Shortly after catheterisation, an ergometric stress-test was performed to examine all recipients by means of thallium-201 SPECT. In each patient, 20 segments of the left ventricle were evaluated using a score system of differentiate between persistent defects, redistribution, and reverse redistribution. A score was developed that measured the degree of inhomogeneity and severity of perfusion defects, respectively. Findings on scintigraphy were correlated to coronary intravascular ultrasound findings. RESULTS: At first investigation, mean intimal index of all evaluated coronary cross-sectional areas was 0.06 +/- 0.1. Sixty-four cross-sectional areas demonstrated a three-layer appearance of the vessel wall, mean circumferential extension was 72 +/- 122 degrees. Thallium scintigraphy demonstrated a total of 336 (40%) pathological left ventricular segments; 168 (20%) were regarded as permanent defects, 67 (8%) demonstrated redistribution and 101 (12%) showed reverse redistribution. The score of inhomogeneity was calculated as 5.8% +/- 2.6%. In the subgroup of patients at the follow-up study, the score was 6.4 +/- 2.8%. There was no correlation between intimal index and the score, nor could any correlation be confirmed between the score and the circumferential extension of a three-layer appearance of the vessel wall. At second investigation, no significant differences of intimal index (0.05 +/- 0.07) or circumferential extension of a three-layer appearance of the vessel wall (74 +/- 118 degrees) could be confirmed. The score was slightly, but significantly increased to 8.1 +/- 4.5% at the second investigation (P < 0.05). CONCLUSION: Early after orthotopic heart transplantation, pathologic thallium distribution patterns of the left ventricle could be observed. These pathological patterns did not correlate with the extent of diffuse coronary vessel wall alterations identifiable by intravascular ultrasound. After more than 1 year, the degree of scintigraphic abnormalities increased significantly, not accompanied by an increase of diffuse coronary vessel wall alterations.

Adult↗
PubMed1989

Localization of coronary artery narrowings by applying R-wave amplitude correction to exercise-induced ST depression in angina pectoris and single-vessel coronary artery narrowing.

This study investigated whether coronary artery narrowings can be localized by applying R-wave amplitude correction to exercise-induced ST depression in multiple unipolar precordial lead electrocardiography using 20 electrodes covering the left chest wall. Ten normal subjects and 29 patients with stable angina pectoris and single-vessel coronary artery narrowing (greater than or equal to 75% luminal diameter stenosis in only 1-vessel) participated. Of the 29 patients, 5 had left main coronary artery disease (CAD), 14 had left anterior descending CAD, 4 had right CAD and 6 had left circumflex CAD. The exercise-induced ST depression with R-wave amplitude correction was defined as the exercise-induced ST depression divided by the R-wave amplitude. The 20 points of the lead system were divided into 4 areas: the left main, left anterior descending, right and left circumflex coronary arteries. Coronary artery narrowing was supposed to be in an artery corresponding to the area where the maximal value of the exercise-induced ST depression with and without R-wave amplitude correction was situated. By applying R-wave amplitude correction, the diagnostic ability of localization of coronary artery narrowings was improved significantly from 52% to 86% (p less than 0.005). In particular, localization of the left main coronary artery narrowing was correctly diagnosed in 100% (5 of 5) of angina pectoris patients with left main CAD.

Aged↗
PubMed1996

Operation for two-vessel coronary artery disease: midterm results of bilateral ITA grafting versus unilateral ITA and saphenous vein grafting.

BACKGROUND: Several studies have demonstrated that single internal thoracic artery (ITA) grafting achieves better results than the use of vein grafts alone, but it is less clear whether bilateral ITA grafting produces better long-term results than a single ITA graft to the left descending coronary artery does. METHODS: We analyzed the early and midterm results of the surgical treatment of two-vessel coronary artery disease (left anterior descending artery and right coronary artery) in two groups of 80 consecutive patients operated on between 1985 and 1989 who received either a bilateral ITA graft or a unilateral ITA graft combined with a saphenous vein graft. Patients were selected from a data base so as to be rigorously matched for demographic and clinical factors as well as angiographic variables, with the researcher being blinded to any additional intraoperative or postoperative data. Follow-up examination was performed after a mean postoperative interval of 8 years. RESULTS: Univariate analysis showed a somewhat higher incidence of sternal complications in the bilateral ITA group (4.8% versus 1.2%; p < 0.02) and a significantly lower reintervention-free survival at 8 years in the group of patients who received a unilateral ITA and saphenous vein graft (84% +/- 5.5% versus 95% +/- 1.5%; p < 0.02). The latter was predominantly due to the development of significant main stem lesions necessitating a redo procedure during the follow-up interval or to the need for percutaneous coronary angioplasty of circumflex artery lesions that were not critical at the time of the initial operation. Perioperative risk was similar in both groups of patients. Old age and a history of congestive heart failure were the most important predictors of perioperative mortality and morbidity for patients receiving bilateral ITAs. Multivariate analysis did not demonstrate any benefit from bilateral arterial grafting over unilateral ITA bypass combined with saphenous vein grafting in terms of overall survival and event-free and intervention-free survival. CONCLUSIONS: Although bilateral ITA grafting can be performed with a perioperative risk comparable with that for unilateral ITA and saphenous vein grafting, long-term results (up to 8 years) of surgically treated two-vessel coronary artery disease are not improved by bilateral ITA grafting.

Aged↗
PubMed1996

Comparison of defect size between thallium-201 and technetium-99m tetrofosmin myocardial single-photon emission computed tomography in patients with single-vessel coronary artery disease.

Defect size on exercise-rest technetium (Tc)-99m tetrofosmin myocardial perfusion imaging was compared with that on exercise-reinjection thallium-201 imaging with 20 patients with 1-vessel coronary artery disease. In each patient, exercise-reinjection thallium-201 single-photon emission computed tomography (SPECT) and exercise-rest Tc-99m tetrofosmin SPECT imaging were performed. For visual analysis of the obtained SPECT images, the left ventricular myocardium was divided into 20 segments based on 3 short-axis slices from the apical, middle, and basal ventricular levels. For quantitative analysis, a square region of interest was placed on the center of each segment which was used for visual analysis, and relative regional activity to the normal reference region was calculated for each segment. By visual interpretation of the images, exercise Tc-99m tetrofosmin imaging showed a smaller defect size than exercise thallium-201 imaging (6.9 +/- 3.9 vs 8.8 +/- 3.0 segments, p <0.01). In contrast, rest Tc-99m tetrofosmin imaging showed a defect size similar to that on reinjection thallium-201 imaging (5.9 +/- 3.6 vs 5.6 +/- 3.9 segments, p = NS). Similarly, the mean defect sizes during exercise determined by quantitative analysis were smaller on Tc-99m tetrofosmin SPECT than those on thallium-201 SPECT at all tested threshold cutoff points ranging from 50% to 70%, whereas there were no significant differences in defect sizes between rest Tc-99m tetrofosmin and reinjection thallium-201 imaging. These data indicate that exercise Tc-99m tetrofosmin SPECT defect size determined either by visual analysis or by quantitative analysis may be smaller than on exercise thallium-201 SPECT.

Aged↗