[Diagnostic test of pulse wave analysis: augmentation index (AI) for arteriosclerosis].
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Aorta↗
Biomedical subjects
Kenji Takazawa
Publications and source records attributed to Kenji Takazawa.
[Influence of serum homocysteine level on coronary atherosclerosis in Japanese].
OBJECTIVES: This study investigated the relationship between serum homocysteine level and coronary artery disease in Japanese. METHODS: Serum homocysteine level was measured in 200 consecutive patients who underwent coronary angiography for the assessment of ischemic heart disease. Patients with acute myocardial infarction were excluded, so 197 patients were included in this study. The patients were classified into four groups based on number of diseased vessels identified by coronary angiography: no significant stenosis group (non-vessel group), one-vessel group, two-vessel group, and three-vessel group. More than 50% stenosis was defined as diseased vessels. RESULTS: Serum homocysteine level in the three-vessel group (13.5 +/- 8.0 microM) was significantly higher than that in the non-vessel group (9.9 +/- 2.7 microM), one-vessel group (9.1 +/- 2.3 microM), and two-vessel group (10.4 +/- 3.3 microM). Patients were classified into quartile groups according to the serum homocysteine level. The number of diseased vessels and frequency of three-vessel disease tended to be higher with increasing serum homocysteine level. There was no significant relationship between serum homocysteine level and coronary risk factors (diabetes mellitus, hyperlipidemia, smoking habit) except hypertension. Multivariate analysis for the predictor of number of diseased vessels showed diabetes mellitus, hypertension, and serum homocysteine level were independent predictors. CONCLUSIONS: Elevation of plasma homocysteine level is related to the severity of coronary artery disease in Japanese.
Aged↗
Reliability of pressure-derived myocardial fractional flow reserve in assessing coronary artery stenosis in patients with previous myocardial infarction.
In 167 patients with suspected coronary artery disease, 74 of whom had myocardial infarction (MI), measurement of myocardial fractional flow reserve (FFR) in previous infarction territories, using a cut-off point of 0.75, showed a sensitivity of 79% and a specificity of 79% for myocardial ischemia as demonstrated by thallium-201 myocardial imaging. This sensitivity and specificity were similar to a sensitivity of 79% and a specificity of 72% observed in territories not related to MI. In addition, a receiver-operating characteristic curve analysis revealed that the best predictability of FFR for myocardial ischemia was between 0.74 and 0.76, regardless of the presence or absence of MI.
Aged↗
Venous coronary artery bypass grafting: late results of a 15-year actuarial follow-up in 486 patients.
PURPOSE: The aim of this study was to clarify the long-term results of venous coronary artery bypass grafting in Japanese patients. METHODS: The study population included 492 patients who underwent venous coronary artery bypass procedures at the Department of Cardiothoracic Surgery of Juntendo University from January 1984 to December 1989. The great majority of patients, 420 of 492 (85.4%), were males, and the mean patient age was 61.1 years (range: 32-82 years). The disease conditions included single-vessel disease in 32 patients (6.5%), double-vessel disease in 111 patients (22.6%), triple-vessel disease in 251 patients (51.2%), and 50% or more stenosis of the left main coronary artery in 98 patients (19.9%). A mean of 2.4 grafts was used per patient. RESULTS: The 15-year survival rate was 57.7%. The 15-year actuarial cardiac survival and cardiac event-free survival were 81.3% and 51.3%, respectively. The 15-year actuarial freedom from reoperation and myocardial infarction were 87.5% and 92.1%, respectively. Of 192 patients who died during the follow-up period, 62 deaths were due to cardiac causes (32.3%), 43 were due to malignant neoplasms (22.4%), and 25 were due to cerebral vascular accidents (13.0%). CONCLUSION: The prognosis of Japanese patients undergoing coronary artery bypass grafting may therefore be more favorable than that of Western patients. In addition, diabetes mellitus was an independent risk factor for both cardiac death and cardiac events.
Adult↗
Metal allergy to stainless steel wire after coronary artery bypass grafting.
To our knowledge, this is the first reported case of a manganese metal allergy to stainless steel wire. A 51-year-old man suffered from a refractory pruritic erythematous wheal after the insertion of a stainless steel wire. The patch test showed strong reactions to manganese, one of the constituents of stainless steel wire. After the removal of all stainless steel wires, the symptoms were much improved, except for mild pruritus on his face.
Bone Wires↗
Coronary flow--pressure relationship distal to epicardial stenosis.
To assess the coronary flow velocity - pressure relationship distal to a stenosis, and to evaluate the influence of microvascular abnormalities on this relationship, coronary flow velocity and coronary pressure were measured simultaneously in 38 patients (42 vessels). The instantaneous peak coronary flow velocity was plotted against the simultaneous measured distal coronary pressure, and the slope of the relation in the phase of diastolic flow decrease was calculated as the flow - pressure slope index (FPSI) and the X-intercept of the slope was calculated as zero-flow pressure (Pzf). The slope of the curve increased from 2.0+/-2.6 to 4.5+/-4.1 (p<0.001) and the X-intercept decreased from 42+/-16 to 27+/-13 mmHg (p<0.001) after papaverine injection. After successful coronary intervention, Pzf increased from 23+/-10 to 35+/-11 (p<0.01) and FPSI decreased from 6.8+/-5.1 to 3.5+/-1.8 (p<0.05). Pzf was higher in patients with an old myocardial infarction. It is feasible to assess the relationship between coronary flow and pressure distal to a stenosis in the clinical setting, and the relationship may provide additional information regarding coronary microcirculation. Microvascular abnormalities may play an important role in the coronary flow - pressure relationship distal to stenosis.
Aged↗
[Usefulness of coronary flow velocity measurement by transthoracic Doppler echocardiography in patients with acute coronary syndrome].
OBJECTIVES: To evaluate the usefulness of left anterior descending coronary artery (LAD) flow measured by transthoracic Doppler echocardiography (TTDE) in patients with acute coronary syndrome. METHODS: Thirty consecutive patients with acute coronary syndrome in the LAD territory and unstable angina or non-ST-segment elevation myocardial infarction required decisions on the need for emergency coronary angiography. The diastolic peak flow velocity was measured in the distal segment of the LAD under guidance of color Doppler echocardiography in the emergency room. If LAD flow was not detected within 10 min, the coronary flow was judged as under the detection limit. The results of TTDE were compared with the Thrombolysis in Myocardial Infarction (TIMI) grade of LAD determined by coronary angiography, which was performed within 1 week (mean 2.5 +/- 1.5 days) in all patients. RESULTS: Coronary flow was not detected by TTDE in six patients who had TIMI grade 1 or 0. The diastolic peak flow velocity in 19 patients with TIMI 3 was higher than that in 5 patients with TIMI 2 (20.1 +/- 4.1 vs 10.9 +/- 2.3 cm/sec, p = 0.0001). A diastolic peak flow velocity of 14 cm/sec was the optimal cut-off value for the prediction of TIMI 3, with a sensitivity of 95% and a specificity of 100%. CONCLUSIONS: Coronary flow velocity measured by TTDE closely reflected the TIMI grade. Coronary flow measurement by TTDE is useful to decide the treatment strategy for patients with acute coronary syndrome in the emergency room.
Aged↗
Coronary pressure measurement after stenting predicts adverse events at follow-up: a multicenter registry.
BACKGROUND: Coronary stenting is associated with a restenosis rate of 15% to 20% at 6-month follow-up, despite optimum angiographic stent implantation. In this multicenter registry, we investigated the relation between optimum physiological stent implantation as assessed by poststent fractional flow reserve (FFR) and outcome at 6 months. METHODS AND RESULTS: In 750 patients, coronary pressure measurement at maximum hyperemia was performed after angiographically apparently satisfactory stent implantation. Poststenting FFR was calculated and related to major adverse events (including need for repeat target vessel revascularization) at 6 months. In 76 patients (10.2%), at least 1 adverse event occurred. Five patients died, 19 experienced myocardial infarction, and 52 underwent at least 1 repeat target vessel revascularization. By multivariate analysis, FFR immediately after stenting was the most significant independent variable related to all types of events. In 36% of the patients, FFR normalized (>0.95), and event rate was 4.9% in that group. In 32% of the patients, poststent FFR was between 0.90 and 0.95, and event rate was 6.2%. In 32% of patients, poststent FFR was <0.90, and event rate was 20.3%. In 6% of the patients, FFR was <0.80, and event rate was 29.5% (P<0.001). CONCLUSIONS: FFR after stenting is a strong independent predictor of outcome at 6 months.
Blood Pressure↗
Off-pump coronary artery bypass grafting in a patient with liver cirrhosis.
We report a case of unstable angina pectoris and alcohol-related Child-Pugh class B cirrhosis. The patient was a 60-year-old man who was admitted to hospital with chest pain. He had previously been diagnosed to have Child B cirrhosis due to alcoholic liver dysfunction at 58 years of age. He also had experienced ruptured esophageal varices, moderate ascites, and hyperammonemia. We performed percutaneous catheter intervention; however, he developed re-stenosis in the right coronary artery, and progression in the disease in other coronary arteries. We then performed coronary artery bypass grafting on the beating heart without cardiopulmonary bypass. He was discharged on the 13th postoperative day without any complications. This case demonstrated that off-pump coronary artery bypass grafting was safe for such a patient.
Angina, Unstable↗
Laparoscopic cholecystectomy after coronary artery bypass grafting using the right gastroepiploic artery: report of a case.
A laparoscopic cholecystectomy (LC) was successfully performed on a 61-year-old man who had undergone coronary artery bypass grafting (CABG) using the right gastroepiploic artery (RGEA). He complained of right hypochondralgia 20 days after CABG. Gallstones were diagnosed and a cholecystectomy was performed 9 months after CABG. Under general anesthesia, the operation was performed using a pneumoperitonium. When a laparoscope was inserted, the RGEA pedicle could be clearly recognized. The pedicle obstructed the operating field and made the working space narrower than usual. No ST changes on the electrocardiogram were seen during LC, especially during the initiation of pneumoperitonium, the insertion of the ports, or when retracting the gallbladder. The postoperative course was uneventful. To avoid complications, care should be taken not to stretch the RGEA pedicle during LC, and careful monitoring of the electrocardiogram is also necessary. It is difficult to view the operating field and the RGEA pedicle together. It is therefore better to insert another laparoscope for concomitant monitoring of the RGEA pedicle.
Cholecystectomy, Laparoscopic↗
Methods and devices for measuring arterial compliance in humans.
This review analyses methods and devices used worldwide to evaluate the arterial stiffness. Three main methodologies are based upon analysis of pulse transit time, of wave contour of the arterial pulse, and of direct measurement of arterial geometry and pressure, corresponding to regional, systemic and local determination of stiffness. They are used in clinical laboratory and/or in clinical departments. Particular attention is given to the reproducibility data in literature for each device. This article summarizes the discussion of the dedicated Task Force during the first Conference of Consensus on Arterial Stiffness held in June 2000 (Paris, France).
Arteries↗
Long-term results for aortic valve replacement with small aortic annulus.
We determined whether aortic prosthesis size influences survival and hemodynamic function. Eighty-nine patients who underwent small aortic valve replacement were followed. The small internal orifice area index (IOAI) group was defined as having an internal orifice area/body surface area ratio of < or = 1.3 cm(2)/m(2) (n = 34). The control group was defined as having an IOAI >1.3 cm(2)/m(2) (n = 55). The actuarial survival rate at 10 years was 74.5% in the small IOAI group and 75% in the control group (NS). Freedom from valve-related impairment at 10 years was 87% in the small IOAI group and 85% in the control group (NS). Postoperative pressure gradients were higher in the small IOAI group (p < 0.05). Left ventricular mass index decreased in both groups (albeit nonsignificantly in the small group, but significantly decreased in the control group). The long-term results of aortic valve replacement for patients with small aortic annulus were satisfactory. However, the postoperative pressure gradient through the prosthesis and left ventricular hypertrophy remained at a high level in the small IOAI group.
Adolescent↗
Correlation between thallium-201 myocardial perfusion defects and the functional severity of coronary artery stenosis as assessed by pressure-derived myocardial fractional flow reserve.
Although a relationship between the coronary pressure-derived fractional flow reserve (FFR) and the presence of myocardial ischemia as demonstrated by radionuclide imaging has been reported in a select group of patients, it remains to be established whether this relation also holds true in actual clinical settings with a heterogeneous group of patients. Accordingly, 194 coronary vessels and their supply territories were evaluated in 165 consecutive patients with suspected or known coronary artery disease. An FFR <0.75, which is regarded as indicative of functionally important stenosis, showed a significant correlation with the redistribution of (201)Tl (p<0.0001), with a sensitivity of 79% and specificity of 73%. In 70 infarct-related coronary arteries, the sensitivity and specificity were 79% and 75%, respectively, whereas in the 124 remaining vessels that were not related to the myocardial infarct, the sensitivity and specificity were 80% and 72%, respectively. In addition, the FFR exhibited a significant inverse correlation with the (201)Tl reversibility score (r=-0.62; p<0.0001). These results suggest that the FFR has a significant relationship with scintigraphic evidence of myocardial ischemia and can be regarded as a marker of its presence or absence in patients in actual clinical settings.
Aged↗
[Prediction of in-stent restenosis by measurement of fractional flow reserve and the influence of diabetes mellitus].
OBJECTIVES: This study tried to predict in-stent restenosis by the measurement of fractional flow reserve and to evaluate the effect of diabetes mellitus control on the relationship between in-stent restenosis and fractional flow reserve. METHODS: Fractional flow reserve was measured in 62 patients (mean age 61 +/- 9 years, 32 with angina pectoris and 30 with myocardial infarction) after stent implantation. The patients were divided into three groups according to the value of HbA1c and fasting blood sugar (FBS): Group P (HbA1c > or = 6.5% or FBS > or = 126 mg/dl, n = 15), Group G (6.5% > HbA1c > or = 5.8% or 126 > FBS > or = 100 mg/dl, n = 12), and Group N (HbA1c < 5.8% and FBS < 100 mg/dl, n = 35). The relationship between fractional flow reserve at the end point of stent implantation and target lesion revascularization (TLR) was evaluated. RESULTS: In all patients, fractional flow reserve was 0.89 +/- 0.17 and percentage diameter stenosis was 17.6 +/- 11.6% after stent implantation. The TLR rate was 21%. Fractional flow reserve was significantly lower in patients with TLR (0.85 +/- 0.08 vs 0.91 +/- 0.06, p < 0.01). Fractional flow reserve was significantly lower in patients with TLR in Groups N and G (Group N: 0.85 +/- 0.04 vs 0.91 +/- 0.06, p < 0.05, Group G: 0.77 +/- 0.06 vs 0.91 +/- 0.05, p < 0.01). Fractional flow reserve showed no significant difference between patients with TLR and without TLR in Group P (0.85 +/- 0.10 vs 0.87 +/- 0.08, p = NS). In patients with optimal results (fractional flow reserve > or = 0.90), TLR rate was 60% in Group P, 0% in Group G and 0% in Group N. CONCLUSIONS: Fractional flow reserve after stent implantation is useful for the prediction of TLR in patients without diabetes mellitus. However, diabetic control in patients with diabetes mellitus might be attributable to TLR rather than fractional flow reserve.
Aged↗
[Measurement of fractional and coronary flow reserve using dual sensor guide wire].
OBJECTIVES: Fractional flow reserve and coronary flow reserve (CFR) are indices of the severity of coronary artery stenosis influenced by both epicardial and microcirculatory dysfunction. The CFR was measured using the new pressure guide wire with thermal sensor (dual sensor guide wire) on the basis of the thermodilution principle (CFR-thermo), and compared to the CFR as measured by the Doppler method (CFR-Doppler), and the relationships were evaluated between CFR-thermo, fractional flow reserve and stress myocardial scintigraphy. METHODS AND RESULTS: CFR-thermo and CFR-Doppler were measured in 14 patients (20 vessels) by the dual sensor guide wire and Doppler guide wire, respectively. A significant positive correlation was found between CFR-Doppler and CFR-thermo (y = 0.80 x + 0.10, r = 0.70, p < 0.0001). Stress myocardial perfusion single photon emission computed tomography (SPECT) was performed before coronary angiography in 56 patients (70 vessels), and then fractional flow reserve and CFR-thermo were measured using the dual sensor guide wire. CFR-thermo and fractional flow reserve were significantly lower in coronary segments with positive SPECT image (n = 32) than in coronary segments with negative SPECT image (n = 38) (1.29 +/- 0.24 vs 1.96 +/- 0.69, p < 0.0001; 0.61 +/- 0.13 vs 0.85 +/- 0.09, p < 0.0001). The cut-off values of CFR-thermo and fractional flow reserve for detection of ischemic segments demonstrated by SPECT image were 1.47 and 0.76, respectively. The sensitivity and specificity for detecting ischemia were 78% and 84% for CFR-thermo, 88% and 92% for fractional flow reserve, respectively. CONCLUSIONS: A significant correlation was found between CFR-thermo measured by the thermodilution principle using the dual sensor guide wire and CFR measured by the Doppler method. CFR-thermo measured by the dual sensor guide wire may be useful to detect myocardial ischemia.
Coronary Circulation↗