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1 Kobe University Repository : Kernel タイトル Title 著者 Author(s) 掲載誌 巻号 ページ Citation 刊行日 Issue date 資源タイプ Resource Type 版区分 Resource Version 権利 Rights DOI JaLCDOI URL Relation of Aortic Distensibility and Pulse Wave Velocity to the Degree of Coronary Artery Stenosis Ishikawa, Yuichi / Miyazaki, Nobuhiro / Mukohdani, Jun-ichi / Watanabe, Naoya / Taniguchi, Takahiro / Yokoyama, Mitsuhiro Bulletin of allied medical sciences Kobe : BAMS (Kobe),11: Departmental Bulletin Paper / 紀要論文 publisher PDF issue:

2 Relation of Aortic Distensibility and Pulse Wave Velocity to the Degree of Coronary Artery Stenosis Yuichi Ishikawa l, Nobuhiro Miyazaki 2, lun-ichi Mukohdani 2./, Naoya Watanabe 2, Takahiro Taniguchi 2 and Mitsuhiro Yokoyama 2 We investigated the correlation of aortic compliance and aortic pulse wave veloc- I ity (PWV) with the degree of the coronary stenosis. Invasive-PWV (IPWX) measurements were carried out in 38 male and 11 female patients, ranging in age from 17 to 71 years old (mean age 54.4 years old). We measured IPWV in ascending, thoracic and abdominal aorta and also in whole aorta by using catheter-tip manometer during diagnostic catheterization and coronary angiography. Tarazi's index (pulse pressurel stroke volume) and diastolic blood pressure decay (DBPD, Simon's method) were also measured as the indicator of the arterial compliance. Balcon's method and Gensini's method were used as the coronary stenotic indx (csi). IPWV s in ascendig, thoracic and abdomonal aorta were 9.42 ± 3.96m/sec, 7.34 ± 2.17 mlsec and 8.42 ± 2.43 mlsec, respectively and the thoracic aorta was the most compliant aorta (p < 0.05). IPWV was positively correlated with Tarazi's index (r = 0.733,. P < 0.001) and was negativelycorrelated with DBPD (r = , p < 0.001). IPWV was correlated to CSI by Gensini and Balcon, respectively (r = 0.568, p < and r = , p < 0.001). In conclusion, IPWV was well correlated with other indices of arterial compliance and predicted the existence of the significant coronary stenosis. PWV was useful method to know the aortic characteristics in patients with arteriosclerosis. Key Words Pulse wave velocity, aortic distensibility, aortic atherosclerosis, coronary atherosclerosis. INTRODUCTION Pulse wave velocity (PWV) has been used as an index of the degree of aortic atherosclerosis. (1) In this paper we evaluated the relation of PWV to other indices of vascular compliance such as Tarazi's index and Faculty of Health Science! and First Department of Internal Medicine 2, Kobe University School of Medicine diastolic blood pressure decay (Simon's method). The initial site of arteriosclerosis is at aorta, especially abdominal aorta. If the correlation between the severities of aortic and coronary atherosclerosis exist, it is possible to predict coronary atherosclerosis by measuring PWV in aorta. We investigated the relation of severity of aortic atherosclerosis to severity of coronary atherosclerosis in patients who underwent diagnostic catheterization and coronary angiography and found a close relationship. SUBJECTS AND METHODS Forty nine patients (38 male and 11 female) who underwent diagnostic Vol. 11, 1995 Bulletin of Allied Medical Sciences, Kobe 81

3 Y. Ishikawa et al. catheterization were investigated, 35 patients with ischemic heart disease, 9 with chest pain syndrome, 3 with cardiomyopathy and 2 with congenital heart disease, ranging in age 1 7 to 71 years old (mean age 54.2 years old). The number of patients with 0 vessel disease was 19, patients with 1 vessel 14, patients with 2 vessel disease 8, and patients with 3 vessel disease 8. THE MEASUREMENTS OF IN VASIVE PULSE WAVE VELOC ITY (PWV). During diagnostic. catheterization, we inserted a catheter-tip manometer (Miller 5F) from a femoral artery and advanced to the position 2 cm upper from the aortic valves and measured aortic pressure (reference position) and then drew back the manometer by 10 cm (ascending aorta), by 20 cm (thoracic aorta), and by 20 cm (abdominal aorta) and measured aortic pressure in each aortic site. We recorded the aortic pressure curves and electrocardiogram (ECG) simultanenously using mingography (Siemens) at 100mm/ sec of paper speed. We calculated PWV as following equation: the distance between each manometer/the time from the onset of Q wave in ECG to the onset of the upstroke of pressure curve (Fig.l) THE MEASUREMENTS OF AOR TIC ARTERIAL COMPLIANCE We calculated Tarazi's index (2) which represented systolic aortic compliance as following equation: aortic pulse pressure at reference position / stroke vol ume. We calculated the stroke volume as following equation: cardiac output measured by thermodil ution method / heart rate. We also calculated the diastolic blood pressure decay (DBPD) (3) which represented diastolic aortic compliance as following equation: DBPD= time constant (T) / peripheral vascular resistance (R). T = diastolic time / InPl-lnP2. R = mean aortic pressure / cardiac output (Fig.2). ECG --A~---J\ '""""'-- Figure 1. Measurement of invasive aortic pulse wave veloe ity. THE ASSESSMENT OF CORON ARY STENOTIC INDEX (CSI) We underwent diagnostic coronary angiography by Judkins' method with m ul ti -projections and three doctors who did not know the results of PWV analysed the degree of severity of 82 Bulletin of Allied Medical Sciences, Kobe

4 Pulse wave velocity and coronary stenosis coronary stenosis by the criteria of American Heart Association. We used two methods to calculate coronary stenotic index, namely Gensini's method and Balcon's method (4). ECG dp/dt thoracic aorta was the most compliant vessel compared with ascending aorta (p < O.OOS) and abdominal aorta. (p < O.OS) (Fig.3). PWV AND AORTIC COMPLIANCE PWV was well correlated to Tarazi's index as shown in Fig.4. (y = 0.10Sx-0.080, r = 0.733, p < 0.001). PWV was also correlated to DBPD as shown in Fig.S. (y = x S, r = - O.717,p < 0.001). DBPD was correlated to Tarazi's index (y _ - 0.lS04x + 2.S60, r = ,p<0.001) (Fig.6). Arterial BP (m/s) 15 ~I--ns---...,,pCo.OO5-, rp<o.05--, -~ Figure 2. Measurement of aortic compliances STATISTICAL ANALYSIS We expressed the values as mean + standard deviation. For statistical analysis, we used student's test. Sensitivity, specificity and predictive value were calculated respectively as following: Sensitivity = true positive / true positive + false negative, specificity = true positive /true positive + false negative, specificity = true negative / true negative + false positive, predictive val ue= true positive / true positive+false positive. RESULTS PWV IN EACH AORTA PWV in ascending aorta, thoracic aorta, and abdominal aorta were m/sec, m/sec, and m/sec, respectively. The 10 > ~ a ~ -'-- o~--~--~~~--~~~-- Ascending Thoracic Abdominal Aorta Aorta Iorta Figure 3. Invasive pulse wave velocity in each segment of aorta PWV AND CSI PWV was positively correlated to CSI by Gensini's method method (y = 6.864x r=0.s68, p=o.ool) (Fig.7) and also correlated to CSI by Balcon's method (y = 6.906x , r = , p < 0.001) (Fig.8). Vol. 11,

5 Y. Ishikawa et al. PP/SV (mmhg/ml) 1. 6 N - 49 Y x r P < , I I I I O II I I I I I I I I I I o PWV (m/s) Figure 4. Correlation of Tarazi's index with invasive pulse wave velocity. N 47 Y x oapo r P < I f! I 1.5..,... I I-PWV (m/s) N 47 Y x r p < ,.., 2. I... COl a.. me Z o~ g ~ 1.5,... t\ 1.0 \ PP/SV(mmHg/ml) Figure 5. Correlation of diastolic blood pressure decay with invasive pulse wave velocity. Figure 6. Correlation of diastolic blood pressure decay with Tarezi's index. 84 Bulletin of Allied Medical Sciences, Kobe

6 Pulse wave velocity and coronary stenosis N = 49 Y = 6.864x r = P < en c "4 e. 5 l!) - 03 U 2,......,. I J-PWV (m/s) Figure 7. Correlation of coronary stenotic index (Censini) with invasive pulse wave velocity II., N - 49 Y x I I I r P < I-PWV (m/s) Figure 8. Correlation of coronary stenotic index (Balcon) with invasive pulse wave velocity PREDICTION OF CORONARY ARTERY STENOSIS BY PWV When the PWV more than 7.5m/ sec was defined as abnormal, sensitivity, specificity and predictive value to estimate coronary artery stenosis were 83%, 90%, and 93%, respectively (Table). Vol. 11,

7 Y. Ishikawa et al. Table Relationships between invasive pulse wave velocity and numbers of diseased coronary arteries. 1- PW V (m/s) (!) <{ u avd V D 2 1 2VD 1 3VD DISCUSSION In this study we showed three distinct findings. First, abdominal aortic PWV was faster than thoracic aortic PWV and this indicated that atherosclerosis in abdominal aorta was severer than in thoracic aorta. Second, PWV was well correlated with the the independent indeces of aortic distensibility such as Tarazi's index and DBPD. Third, the progression of aortic atherosclerosis was correlated with the progression of coronary atherosclerosis. McDonald (5) and Farrar (6) reported independently that PWV became faster along the aorta in dog and monkey, respectively. Lathman (7) reported that in nine healthy subjects, there was no difference in PWV in ascending, thoracic and abdominal aorta and iliac artery. In our study including patients with coronary heart disease, abdominal PWV was faster than thoracic PWV. This finding indicated that abdominal aortic athero- sclerosis progressed faster than thoracic aortic atherosclerosis. PWV was well correlated with the Tarazi's index and DBPD. Ventura (8) also reported the correlationships between PWV, Tarazi's index and DBPD. These findings sugessted that aortic mechanical characteristics in systolic and diastolic phase were changed simultaneously as atherosclerosis progressed. However we should note that these mechanical properties change not only by atherosclerosis but other factors such as blood pressure, calcification, drugs and salt intake (9). It has been controversial whether there was a correlation between aortic and coronary atherosclerosis. In pathological study, Stenby reported (10) that there was a close relationship between aortic and coronary atherosclerosis. In the present study, we showed that patients with faster PWV (more than 7.5 m/sec) had good chances to have coronary atherosclerosis and all patients whose PWV 86 Bulletin of Allied Medical Sciences, Kobe

8 Pulse wave velocity and coronary stenosis was more than 10 ml sec had significant coronary stenosis. In conclusion, there was a significant correlation between PWV and the indeces of aortic distensibility. Aortic PWV correlated with the extent of coronary stenosis and and it is possible to predict coronary atherosclerosis by measuring PWV. REFERENCES 1. Bramwell JC. Hill A V: The velocity of the pulse wave in man. Proc Roy Soc B 93: Tarazi RC. Magrin IF Dustan HP: The role of aortic distesibility in hypertension. In Inter national Symposium on Hypertension. Edited by P Miller. ME Safer. Monaco. Boehringer Ingelheim p Simon AC. Safer ME. Levenson JA. et al: An evaluation of large arteries compliance in man. Am J Physiol 237: H Baleon R, Cattel MR, Stone DL. et al: A computer generated index for the assessment of coronary angiography. Acta Med Scand 615 (supp!): McDonald DA: Regional pulse-wave velocity in arterial tree. J Appl Physiol 24: Farrar OJ. Boud MG. Sawyer JK. et al: Pulse wave velocity and morphological changes associated with early atherosclerosis progression in the aortas of cynomolgus monkeys. Cardiovasc Res 18: Lathman RD. Westehof N. Sipkema p. et al: Regional wave travel and reflections along the human aorta: a study with six simultaneous micromanometric pressures. Circulation 72: Ventura H. Messerli FH. Oigman W. et al: Impaired systemic arterial compliance in borderline hypertension. Am Heart J 108: Bentos A. Bouaziz H. Albaladejo p. et al: Carotid artery mechanical properties of Dahl salt-sensitive rats. Hypertension 25: Stenby NH: Atherosclerosis in a defined populalation.an autopsy survey in Malmo. Sweden. Acta Path Microbiol Scand A 194: Vol. 11,