BACKGROUNDCoronary revascularization guided by fractional flow reserve (FFR) is associated with better patient outcomes after the procedure than revascularization guided by angiography alone. It is unknown whether the instantaneous wave-free ratio (iFR), an alternative measure that does not require the administration of adenosine, will offer benefits similar to those of FFR. METHODSWe randomly assigned 2492 patients with coronary artery disease, in a 1:1 ratio, to undergo either iFR-guided or FFR-guided coronary revascularization. The primary end point was the 1-year risk of major adverse cardiac events, which were a composite of death from any cause, nonfatal myocardial infarction, or unplanned revascularization. The trial was designed to show the noninferiority of iFR to FFR, with a margin of 3.4 percentage points for the difference in risk. RESULTSAt 1 year, the primary end point had occurred in 78 of 1148 patients (6.8%) in the iFR group and in 83 of 1182 patients (7.0%) in the FFR group (difference in risk, −0.2 percentage points; 95% confidence interval [CI], −2.3 to 1.8; P<0.001 for noninferiority; hazard ratio, 0.95; 95% CI, 0.68 to 1.33; P = 0.78). The risk of each component of the primary end point and of death from cardiovascular or noncardiovascular causes did not differ significantly between the groups. The number of patients who had adverse procedural symptoms and clinical signs was significantly lower in the iFR group than in the FFR group (39 patients [3.1%] vs. 385 patients [30.8%], P<0.001), and the median procedural time was significantly shorter (40.5 minutes vs. 45.0 minutes, P = 0.001). CONCLUSIONSCoronary revascularization guided by iFR was noninferior to revascularization guided by FFR with respect to the risk of major adverse cardiac events at 1 year. The rate of adverse procedural signs and symptoms was lower and the procedural time was shorter with iFR than with FFR. ( Use of Instantaneous Wave-free R atio in PCI F or the past 20 years, physiological measurements obtained during invasive procedures have been used to guide coronary revascularization. Pioneering work supported the use of flow measurements to make safe decisions about revascularization, 1,2 but this approach was soon superseded by the use of fractional flow reserve (FFR), which measures pressure as a surrogate of flow to estimate the severity of stenosis. 3-5 FFR was successful largely because of its technical simplicity and because clinical trials showed that it was associated with improved clinical outcomes after percutaneous coronary intervention (PCI). 6,7 Consequently, FFR is now included in the appropriate-use criteria for coronary angiography and in the American College of Cardiology-American Heart Association-European Society of Cardiology guidelines; despite these recommendations, its adoption remains limited. [8][9][10] FFR must be measured during maximal hyperemia, which is typically induced with the administration of a potent intravenous or intracoronary vasodilator, such as adenosine. 11 Several studies have...

Abstract-To evaluate the clinical application of the second derivative of the fingertip photoplethysmogram waveform, we performed drug administration studies (study 1) and epidemiological studies (study 2). In study 1, ascending aortic pressure was recorded simultaneously with the fingertip photoplethysmogram and its second derivative in 39 patients with a meanϮSD age of 54Ϯ11 years. The augmentation index was defined as the ratio of the height of the late systolic peak to that of the early systolic peak in the pulse. The negative d/a reflects the late systolic pressure augmentation in the ascending aorta and may be useful for noninvasive evaluation of the effects of vasoactive agents. In study 2, the second derivative of the plethysmogram waveform was measured in a total of 600 subjects (50 men and 50 women in each decade from the 3rd to the 8th) in our health assessment center. The b/a ratio increased with age, and c/a, d/a, and e/a ratios decreased with age. Thus, the second derivative aging index was defined as b-c-d-e/a. The second derivative wave aging index (y) increased with age (x) (rϭ0.80, PϽ0.001, yϭ0.023xϪ1.515). The second derivative aging index was higher in 126 subjects with any history of diabetes mellitus, hypertension, hypercholesterolemia, and ischemic heart disease than in age-matched subjects without such a history (Ϫ0. Key Words: photoplethysmography Ⅲ second derivative wave Ⅲ augmentation index Ⅲ vasoactive agents Ⅲ vascular aging Ⅲ angiotensin Ⅲ nitroglycerin N oninvasive pulse wave analysis is useful for evaluation of vascular load and vascular aging. 1 It is usually measured at the palpable artery, including carotid, femoral, and radial arteries.2 These pulse wave tracings provide more precise information concerning blood pressure changes than systolic and diastolic pressures only. 3 The basic idea of the augmentation index was first described by Murgo et al 4 in 1980 in relation to the reflection return point in the ascending aorta. Kelly et al 2 first used the term "augmentation index" in their 1989 study evaluating age-related changes in AIs. They showed age-related increase in AIs at carotid and radial arteries. Ascending aortic pressure can be divided into 2 components at the anacrotic notch, where maximal flow velocity is observed.2 The early systolic component is caused mainly by left ventricular ejection, and the second component is augmented by peripheral reflection wave.5 PTG detects the changes in the amount of light absorbed by hemoglobin, which reflects changes in blood volume. Wiederhelm et al 6 showed pulsatile pressure changes in vessel down to metaarteriole size that corresponded to pulse tracing. PTG has been used to evaluate arterial compliance in relation to changes in the amplitude of wave, 7 but the wave contour itself is not usually used. The SDPTG has been developed to allow more accurate recognition of the inflection points on the original plethysmographic wave, ie, anacrotic or dicrotic notches. In 1972, Ozawa recorded the first and second derivative waves of P...

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chocardiography is now recognized as an integral diagnostic tool that enables noninvasive quantification of cardiac chamber size, ventricular mass, and function in the clinical setting. Furthermore, technological advancement in Doppler echocardiography enables quantitative assessment of ventricular diastolic function as well as systolic function. Thus, echocardiography has become an important cardiac imaging technique in a number of clinical trials evaluating the efficacy of drug treatments or new therapeutic strategies.A guideline for quantifying cardiac chamber size and function using echocardiography, and references values for Circulation Journal Vol.72, November 2008 these echocardiographic measurements, were provided by the American Society of Echocardiography in conjunction with the European Association of Echocardiography. 1 Likewise, Doppler echocardiographic criteria for assessing left ventricular (LV) diastolic function were provided by the Canadian Consensus, 2 European 3 and American Medical Association guidelines, 4 and diastolic function parameters were reported to decline gradually with age. 5 However, most of these data are derived from American and European populations and because physical 6,7 and racial 8-10 differences can influence cardiac chamber size and function, it is important to evaluate the echocardiographic parameters in other populations. Reference values based on a large Asian population have not been previously reported, although some investigators have reported these values in a small population. 11 In addition, most studies that have investigated the relationship between age and cardiac chamber size and function have focused on a few parameters and have not assessed all of them in a large population.Accordingly, we designed and conducted a multicenter study, the Japanese Normal Values for Echocardiographic Measurements Project (JAMP) study, to determine the normal values for echocardiographic measurements and evaluate the relationship between these parameters and age in a large, healthy Japanese population. J 2008; 72: 1859 -1866 (Received February 27, 2008 revised manuscript received June 11, 2008; accepted June 26, 2008; released online September 29, 2008) Circ

ulse wave velocity (PWV), which reflects arterial stiffness, is a predictor of future cardiovascular events in a general population or patients with either hypertension, diabetes mellitus or end-stage renal diseases. [1][2][3][4] The carotid-femoral PWV measurement is known as a conventional method. 5,6 Recently, brachialankle PWV (baPWV) measurement, which is easier to perform than the use of other noninvasive automatic devices and uses pressure cuffs wrapped on the brachium and ankle, has become available in clinical settings. This method can be used to measure PWV in a large number of subjects. 7,8 baPWV correlates with intima-media thickness of the carotid artery, which is a marker of the severity of atherosclerosis, 9 and a close association between baPWV and aortic PWV has been also demonstrated. 7 However, baPWV measurements include not only the aortic component, but also the muscular arterial component. 7,10 Therefore, the usefulness of baPWV as a predictor of cardiovascular events has yet to be decisively established.PWV is a marker related to the severity of atherosclerosis and the increased arterial stiffness (especially aortic stiffness) causes the increased left ventricular afterload and Circulation Journal Vol.69, July 2005 the impaired coronary blood supply. 9,11 These pathophysiological abnormalities are thought to be involved in the underlying mechanism of influencing the prognosis. [1][2][3][4][5][6] Acute coronary syndrome (ACS) is a critical condition and predicting the prognosis of patients with ACS is crucial for their management. 12,13 Increased aortic stiffness, resulting in the above-mentioned disorders, may have an unfavorable influence on the prognosis of patients with ACS.The present study was conducted to evaluate the usefulness of this simple baPWV measurement as a marker of predicting the prognosis in a clinical setting. We also examined whether the baPWV measurements can be used to predict the prognosis of patients with ACS. Methods Study Population, Follow-up Protocol, Study Endpoints and Endpoint DefinitionsBetween January 2001 and December 2003, 223 consecutive patients with ACS started their follow-up care in the outpatient cardiology department of the Tokyo Medical University Hospital. All of the patients had been hospitalized for the treatment of ACS between January 2001 and December 2003 and had undergone a coronary angiography procedure to confirm the culprit lesion and an echocardioigraphy examination to assess their left ventricular function. During the patients' hospitalization for ACS, percutaneous coronary intervention was conducted, if applicable. The baPWV was measured using the oscillometric method within 5 days before their discharge from the hospital.

During the acute phase of acute coronary syndromes, the severity of nonculprit coronary artery stenoses can reliably be assessed by FFR. This allows a decision about the need for additional revascularization and might contribute to a better risk stratification.

To determine why upper limb blood pressure measurement underestimates the vasodilator effects of nitroglycerin on lowering ascending aortic systolic pressure, we studied 24 patients (58 +/- 11 years, mean +/- SD). Ascending aortic pressure and radial artery pulse calibrated by cuff blood pressure measurement at the brachial artery were recorded simultaneously before and 5 minutes after sublingual administration of 0.3 mg nitroglycerin. Waves were analyzed by a signal processor, and the fourth derivative wave was used to find the early (S1) and late (S2) systolic shoulders (S1 corresponds to the second zero crossing and S2 to the third zero crossing). Before nitroglycerin administration, maximal systolic pressure in the ascending aorta (141 +/- 21 mm Hg) coincided with the late systolic peak in all patients, and in most patients (21 of 24) maximal systolic pressure in the radial artery (140 +/- 19 mm Hg) coincided with the early systolic peak. Maximal systolic pressure decreased more in the ascending aorta than in the radial artery (22 +/- 13 and 11 +/- 11 mm Hg, respectively; P < .001). However, the reduction in the shoulder of late systolic pressure in the radial artery (24 +/- 13 mm Hg) clearly indicated the reduction in maximal systolic pressure (late systolic peak) in the ascending aorta. The augmentation index of the ratio of the height of late systolic pressure to early systolic pressure fell proportionally (r = .74, P < .001) in the radial artery (from 0.88 +/- 0.13 to 0.60 +/- 0.11) and in the ascending aorta (from 1.57 +/- 0.25 to 1.26 +/- 0.24), which indicated the reduction in late systolic pressures.(ABSTRACT TRUNCATED AT 250 WORDS)

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