Factors Influencing Cardiac Sympathetic Nervous Function in Patients With Severe Aortic Stenosis: Assessment by 123I-Metaiodobenzylguanidine Myocardial Scintigraphy.

BACKGROUND: Numerous studies have shown that 123I-metaiodobenzylguanidine (MIBG) scintigraphy, an index of cardiac sympathetic nervous (CSN) activity, is useful for predicting prognosis in patients with heart failure. However, the factors influencing the CSN activity of patients with severe aortic stenosis (AS) remain unclear. METHODS: We enrolled 91 patients with severe AS who underwent 123I-MIBG scintigraphy, coronary computed tomography (CCT), and transthoracic echocardiography. When CCT angiography (CCTA) showed an obstructive epicardial artery, invasive coronary angiography was performed within 1 week of CCTA. RESULTS: There were 21 male and 70 female patients with a mean age of 84±5 years. Eighty-five (85) patients (93%) had hypertension and 13 patients (14%) had diabetes. Two (2) patients (2%) had previous myocardial infarction and eight (9%) had a previous coronary intervention. All patients had severe AS: aortic valve area was 0.63±0.18 cm2 and the mean pressure gradient was 56±19 mmHg. Regarding 123I-MIBG parameters, early heart-to-mediastinum (H/M) ratio was 3.1±0.5, delayed H/M ratio was 2.8±0.6, and the washout rate (WR) was 35%±13%. Multivariable linear regression analysis showed that coronary artery disease (ß=-0.30, p=0.002) was an independent predictor of delayed H/M ratio, and that aortic valve area (ß=-0.20, p=0.048) was an independent predictor of WR. CONCLUSIONS: Our findings suggest that coronary artery disease is an independent predictor of delayed H/M ratio, and aortic valve area is an independent predictor of WR in patients with severe AS.

The Monocyte to High-Density Lipoprotein Cholesterol Ratio Is Associated with Left Ventricular Diastolic Function in Patients with No Significant Perfusion Abnormality.

The monocyte to high-density lipoprotein cholesterol (HDL-C) ratio has been considered to be a prognostic marker. Whether this ratio is associated with left ventricular (LV) diastolic function remains undetermined. We tested the hypothesis that the monocyte to HDL-C ratio is associated with LV diastolic parameters derived from gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with no significant perfusion abnormality.The study population included 196 patients with no significant perfusion abnormalities and preserved ejection fraction. The peak filling rate (PFR) and one-third mean filling rate (1/3 MFR) were obtained as LV diastolic parameters using gated SPECT. Monocyte counts and plasma HDL-C levels were also examined.Significant associations were observed between the monocyte to HDL-C ratio and PFR (r = -0.20; P = 0.005) and 1/3 MFR (r = -0.19; P = 0.009). Multivariate linear regression analysis was performed to determine factors associated with LV diastolic parameters. Age (ß = -0.27; P < 0.001), LV end-diastolic volume (ß = -0.19; P = 0.034), and monocyte to HDL-C ratio (ß = -0.15; P = 0.027) were determined to be significantly associated with PFR. Moreover, age (ß = -0.13; P = 0.007), LV mass index (ß = -0.18; P = 0.037), and the monocyte to HDL-C ratio (ß = -0.13; P = 0.045) were significantly associated with 1/3 MFR.These results demonstrated that the monocyte to HDL-C ratio is associated with LV diastolic function, as derived from gated SPECT in patients with no significant perfusion abnormality.

Frontal QRS-T angle and left ventricular diastolic function assessed by ECG-gated SPECT in the absence of significant perfusion abnormality.

The frontal QRS-T angle, defined as the angle between QRS and T-wave axes, has recently become an area of research interest. We tested the hypothesis that the frontal QRS-T angle is associated with left ventricular (LV) diastolic function in the absence of significant perfusion abnormality using ECG-gated SPECT. One hundred twenty eight patients with no significant perfusion abnormality and preserved LV ejection fraction were enrolled. The peak filling rate (PFR) and the one-third mean filling rate (1/3 MFR) were obtained as LV diastolic parameters on ECG-gated SPECT. There were 115 male and 13 female patients with a mean age of 70 ± 9 years. The PFR and 1/3 MFR were 2.1 ± 0.4/s and 1.2 ± 0.3/s, respectively. The frontal QRS-T angle was 33° ± 31°, ranging from 0° to 151°. There were significant associations of frontal QRS-T angle with PFR (r = - 0.29, p = 0.001) and 1/3 MFR (r = - 0.30, p < 0.001). Multivariate linear regression analysis showed that age (ß = - 0.25, p = 0.003), heart rate (ß = 0.26, p = 0.002), LV ejection fraction (ß = 0.43, p < 0.001) and frontal QRS-T angle (ß = - 0.16, p = 0.03) were significant factors associated with PFR. Also, heart rate (ß = - 0.32, p < 0.001), LV mass index (ß = - 0.19, p = 0.03), LV ejection fraction (ß = 0.30, p < 0.001) and frontal QRS-T angle (ß = - 0.26, p = 0.002) were significant factors associated with 1/3 MFR. Our data suggested that the frontal QRS-T angle was associated with LV diastolic function in the absence of significant perfusion abnormality.

Associations of left ventricular shape with left ventricular volumes and functions assessed by ECG-gated SPECT in patients without significant perfusion abnormality.

Left ventricular (LV) remodeling often results from conditions with an elevated LV hemodynamic load or after myocardial infarction. The present study was undertaken to investigate the associations of LV shape with LV volumes and functions in patients without significant perfusion abnormality. One hundred and sixty-seven patients without significant perfusion abnormality on ECG-gated SPECT were enrolled. LV ejection fraction (LVEF) was obtained for assessing LV systolic function. Peak filling rate (PFR) and one-third mean filling rate (1/3 MFR) were obtained for assessing LV diastolic function. LV shape index (LVSI) was defined as the ratio of the maximum three-dimensional short- and long-axis LV dimension, and varies from 0 (line) to 1 (sphere). There were 125 male and 42 female patients with a mean age of 70 ± 8 years. End-systolic LVSI was 0.49 ± 0.07 (0.34-0.65). End-systolic LVSI was associated with LV end-diastolic volume (r = 0.51, p < 0.001) and LV end-systolic volume (LVESV) (r = 0.64, p < 0.001), and was inversely associated with LVEF (r = - 0.69, p < 0.001), PFR (r = - 0.45, p < 0.001) and 1/3 MFR (r = - 0.26, p = 0.008). End-systolic LVSI was increased with increased LVESV, and was not any more with LVESV of > 40 ml. Multivariate liner regression analysis showed that age (ß = 0.16, p = 0.01), LVESV (ß = 0.20, p = 0.03) and LVEF (ß = - 0.53, p < 0.001) were significantly associated with end-systolic LVSI. Our data suggest that end-systolic LVSI, a measurement of LV shape, has close correlations with LV volumes and functions in patients without significant perfusion abnormality.

Effects of aging on coronary flow reserve in patients with no evidence of myocardial perfusion abnormality.

Coronary flow reserve (CFR) reflects the functional capacity of microcirculation to adapt to blood demand during increased cardiac work. We tested the hypothesis that aging had impacts on coronary flow velocities and CFR in patients with no evidence of myocardial perfusion abnormality on single photon emission computed tomography (SPECT). Seventy-six patients undergoing transthoracic Doppler echocardiography with no evidence of myocardial perfusion abnormality on SPECT were enrolled in this study. CFR was defined as the ratio of hyperemic to resting peak diastolic coronary flow velocity. Patients were divided into the three groups based on age: 17 patients aged less than 70 years (Group I), 38 patients aged 70-79 years (Group II), and 21 patients aged 80 years or more (Group III). Compared with Group I, CFR was significantly lower in Group II (p < 0.01) and Group III (p < 0.01). Multivariate linear regression analysis showed that female (ß = - 0.26, p = 0.03), cigarette smoking (ß = - 0.32, p = 0.004), hemoglobin level (ß = - 0.40, p = 0.001) and LV mass index (ß = 0.24, p = 0.03) were determinants for resting coronary flow velocity. On the other hand, age (ß = -0.30, p = 0.008), hemoglobin level (ß = -0.47, p < 0.001) and LV mass index (ß = 0.24, p = 0.04) were determinants for hyperemic coronary flow velocity. Age was only determinant for CFR (ß = -0.48, p < 0.001). Our data suggested that that aging had a decreased effect on hyperemic coronary flow velocity rather than resting coronary flow velocity, and was further associated with impaired CFR in patients with no evidence of myocardial perfusion abnormality.

Impact of Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Replacement on Changes in Cardiac Sympathetic Nervous Function.

The impact of prosthesis-patient mismatch (PPM) after transcatheter aortic valve replacement (TAVR) on changes in cardiac sympathetic nervous (CSN) function remains unclear. Using 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy, we investigated the impact of PPM after TAVR on CSN activity.We enrolled 44 of 117 patients with severe aortic stenosis who underwent TAVR for analysis in the present study. We conducted 123I-MIBG scintigraphy at baseline and at about 9 months after TAVR. Differences between baseline and post-TAVR 123I-MIBG parameters were compared between cases with and without PPM.There were 17 and 27 patients with and without PPM, respectively. Those without PPM exhibited significantly decreased left ventricular mass index (122 ± 36 g/m2 versus 108 ± 30 g/m2, P < 0.001) following TAVR, whereas those with PPM did not (117 ± 21 g/m2 versus 110 ± 17 g/m2, P = 0.09). Significant improvements in delayed heart-to-mediastinum (H/M) ratio (2.8 ± 0.4 versus 3.0 ± 0.4, P = 0.004) and washout rate (WR) (33% ± 10% versus 24% ± 12%, P < 0.001) were observed after TAVR in patients without PPM but not in those with PPM. Multivariable linear regression analysis revealed PPM to be a negative predictor of improvements in delayed H/M ratio and WR.Delayed H/M ratio and WR improve significantly after TAVR in the absence of PPM, whereas these improvements are not observed in patients with PPM. Hence, the presence of PPM is a negative predictor of improvements in delayed H/M ratio and WR in patients undergoing TAVR.

Coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone improves postprandial endothelial dysfunction in patients with borderline and stage 1 hypertension.

PURPOSE: The purpose of this study was to evaluate acute effects of coffee with a high content of chlorogenic acids and different hydroxyhydroquinone contents on postprandial endothelial dysfunction. METHODS: This was a single-blind, randomized, placebo-controlled, crossover-within-subject clinical trial. A total of 37 patients with borderline or stage 1 hypertension were randomized to two study groups. The participants consumed a test meal with a single intake of the test coffee. Subjects in the Study 1 group were randomized to single intake of coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone or coffee with a high content of chlorogenic acids and a high content of hydroxyhydroquinone with crossover. Subjects in the Study 2 group were randomized to single intake of coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone or placebo coffee with crossover. Endothelial function assessed by flow-mediated vasodilation and plasma concentration of 8-isoprostanes were measured at baseline and at 1 and 2 h after coffee intake. RESULTS: Compared with baseline values, single intake of coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone, but not coffee with a high content of chlorogenic acids and high content of hydroxyhydroquinone or placebo coffee, significantly improved postprandial flow-mediated vasodilation and decreased circulating 8-isoprostane levels. CONCLUSIONS: These findings suggest that a single intake of coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone is effective for improving postprandial endothelial dysfunction. CLINICAL TRIAL REGISTRATION: URL for Clinical Trial: https://upload.umin.ac.jp ; Registration Number for Clinical Trial: UMIN000013283.

Effects of deep inspiration on QRS axis, T-wave axis and frontal QRS-T angle in the routine electrocardiogram.

The frontal QRS-T angle on the electrocardiogram has been described as a variable of ventricular repolarization. We evaluated how deep inspiration affected QRS axis, T-wave axis and frontal QRS-T angle. We also assessed the effects on left ventricular volume on the association using myocardial perfusion SPECT. Fifty patients undergoing ECGs both in resting state and in deep inspiration and subsequent SPECT were enrolled. Frontal QRS-T angle was defined as the absolute value of the difference between the frontal QRS axis and T-wave axis. Change in frontal QRS-T angle was calculated using (QRS-T angle in deep inspiration-QRS-T angle in resting state). In resting state, QRS axis and T-wave axis were 20.9° ± 30.0° and 40.9° ± 36.1°, respectively. Frontal QRS-T angle was 35.9° ± 36.1°. Deep inspiration caused rightward shifts of QRS axis (42.3° ± 29.5°, p < 0.001) and T-wave axis (49.5° ± 39.7°, p < 0.001). However, deep inspiration did not affect frontal QRS-T angle (33.9° ± 35.8°, p = 0.44). Frontal QRS-T angle in deep inspiration had good correlation (r = 0.87, p < 0.001) and agreement with that in resting state. Left ventricular (LV) end-diastolic volume had a significant association with change in frontal QRS-T angle (r = 0.29, p = 0.04). Our data suggest that frontal QRS-T angle in deep inspiration has a good correlation with that in resting state, and the agreement is acceptable. In patients with dilated LV, QRS-T angle in deep inspiration may be susceptible to the overestimation.

Myocardial perfusion defect assessed by single-photon emission computed tomography and frontal QRS-T angle in patients with prior anterior myocardial infarction.

The frontal QRS-T angle is one of the markers of ventricular repolarization. We sought to assess the effects of myocardial perfusion defect on QRS-T angle in patients with prior anterior myocardial infarction (MI). Seventy-one patients with prior anterior MI and 71 age- and sex-matched control subjects having no myocardial perfusion defect were selected. Frontal QRS-T angle was defined as the absolute value of the difference between the frontal plane QRS axis and T-wave axis. The extent of myocardial perfusion defect was determined using myocardial perfusion single-photon emission computed tomography (SPECT). The extent of myocardial perfusion defect of patients with prior anterior MI was 21.8 ± 13.7%. Frontal QRS-T angle was significantly larger in patients with prior anterior MI than control subjects (82° ± 49° vs 30° ± 26°, p < 0.001). Prevalence of abnormal frontal QRS-T angle defined as more than 90° was significantly higher in patients with prior anterior MI than control subjects (42% vs 4%, p < 0.001). Multivariate linear regression analysis showed that age (ß=0.18, p = 0.02) and myocardial perfusion defect (ß = 0.46, p = 0.02) were independent determinants of frontal QRS-T angle. Our results suggest that the extent of myocardial perfusion defect is an independent determinant of frontal QRS-T angle in patients with prior anterior MI.

International Expert Consensus Document on Takotsubo Syndrome (Part II): Diagnostic Workup, Outcome, and Management.

The clinical expert consensus statement on takotsubo syndrome (TTS) part II focuses on the diagnostic workup, outcome, and management. The recommendations are based on interpretation of the limited clinical trial data currently available and experience of international TTS experts. It summarizes the diagnostic approach, which may facilitate correct and timely diagnosis. Furthermore, the document covers areas where controversies still exist in risk stratification and management of TTS. Based on available data the document provides recommendations on optimal care of such patients for practising physicians.

International Expert Consensus Document on Takotsubo Syndrome (Part I): Clinical Characteristics, Diagnostic Criteria, and Pathophysiology.

Takotsubo syndrome (TTS) is a poorly recognized heart disease that was initially regarded as a benign condition. Recently, it has been shown that TTS may be associated with severe clinical complications including death and that its prevalence is probably underestimated. Since current guidelines on TTS are lacking, it appears timely and important to provide an expert consensus statement on TTS. The clinical expert consensus document part I summarizes the current state of knowledge on clinical presentation and characteristics of TTS and agrees on controversies surrounding TTS such as nomenclature, different TTS types, role of coronary artery disease, and etiology. This consensus also proposes new diagnostic criteria based on current knowledge to improve diagnostic accuracy.

Coronary Artery Calcium Is Associated with Left Ventricular Diastolic Function Independent of Myocardial Ischemia.

It has been shown in several studies that coronary artery calcium (CAC) burden or CAC progression is associated with heart failure. We tested the hypothesis that the extent of CAC is associated with left ventricular (LV) diastolic parameters derived from gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with no evidence of myocardial ischemia.157 patients undergoing coronary computed tomography (CT), gated SPECT, and transthoracic echocardiography (TTE) were enrolled in this study. The CAC score was calculated according to the Agatston method. The peak filling rate (PFR) and the one-third mean filling rate (1/3MFR) were obtained as LV diastolic parameters.There were 139 patients with CAC and 18 patients without. The CAC score ranged from 0 to 4,976. There were no significant differences in the LV end-diastolic volume (LVEDV) (61 ± 21 mL versus 62 ± 22 mL, P = 0.79) and LV ejection fraction (LVEF) (66 ± 9% versus 68 ± 9%, P = 0.43). Patients with CAC had lower PFR than those without (2.2 ± 0.5 EDV/s versus 2.6 ± 0.7 EDV/s, P = 0.03). Multivariate linear regression analysis showed that ln (CAC score + 1) was significantly associated with PFR (ß = -0.20, P = 0.01) and 1/3MFR (ß = -0.18, P = 0.049).Our data suggest that the extent of CAC is inversely associated with LV diastolic parameters derived from gated SPECT independent of myocardial ischemia.

Effects of aortic tortuosity on left ventricular diastolic parameters derived from gated myocardial perfusion single photon emission computed tomography in patients with normal myocardial perfusion.

Aortic tortuosity is often found on chest radiograph, especially in aged patients. We tested the hypothesis that aortic tortuosity was associated with LV diastolic parameters derived from gated SPECT in patients with normal myocardial perfusion. One-hundred and twenty-two patients with preserved LV ejection fraction and normal myocardial perfusion were enrolled. Descending aortic deviation was defined as the horizontal distance from the left line of the aortic knob to the most prominent left line of the descending aorta. This parameter was measured for the quantitative assessment of aortic tortuosity. Peak filling rate (PFR) and one-third mean filling rate (1/3 MFR) were obtained from redistribution images as LV diastolic parameters. Descending aortic deviation ranged from 0 to 22 mm with a mean distance of 4.5 ± 6.3 mm. Descending aortic deviation was significantly correlated with age (r = 0.38, p < 0.001) and estimated glomerular filtration rate (eGFR) (r = - 0.21, p = 0.02). Multivariate linear regression analysis revealed that eGFR (ß = 0.23, p = 0.02) and descending aortic deviation (ß = - 0.23, p = 0.01) were significantly associated with PFR, and that only descending aortic deviation (ß = - 0.21, p = 0.03) was significantly associated with 1/3 MFR. Our data suggest that aortic tortuosity is associated with LV diastolic parameters derived from gated SPECT in patients with normal myocardial perfusion.

Effect of fibrillatory wave amplitude on coronary blood flow as assessed by thrombolysis in myocardial infarction frame count in patients with atrial fibrillation.

Atrial fibrillation (AF) is the most common arrhythmia, characterized by a lack of atrial contraction and an irregular ventricular rhythm. We assessed the effect of fibrillatory wave amplitude on coronary blood flow in patients with AF using the thrombolysis in myocardial infarction (TIMI) frame count. Sixty-one patients with AF persisting for longer than 30 days were included. For controls, 61 age- and sex-matched patients with sinus rhythm were selected. Coarse AF was defined as any fibrillatory wave ≥ 1 mm and fine AF as any fibrillatory wave < 1 mm. Mean TIMI frame count was significantly higher in patients with AF than in those with sinus rhythm (18 ± 4 vs 30 ± 11, p < 0.001). Multivariate analysis showed that AF was the only determinant of mean TIMI frame count (ß = 0.48, p < 0.001). Among patients with AF, 32 had coarse AF and 29 had fine AF. Left atrial volume index (54 ± 14 vs 64 ± 21 ml/m2, p = 0.03) was significantly larger, and mean TIMI frame count (26 ± 7 vs 35 ± 12, p < 0.001) was significantly higher in patients with fine AF than in those with coarse AF. Multivariate analysis showed that hypertension (ß = - 0.29, p = 0.01) and a fine fibrillatory wave (ß = 0.33, p = 0.007) were determinants of mean TIMI frame count. Our data suggest that coronary blood flow is reduced in patients with AF compared with those with sinus rhythm, and that a fine fibrillatory wave is a major determinant of reduced coronary blood flow in patients with AF.

Association of QRS duration with left ventricular volume and ejection fraction after anterior myocardial infarction assessed by gated single photon emission computed tomography.

BACKGROUND: Even intermediate QRS prolongation without bundle branch block is associated with worse clinical outcome after myocardial infarction (MI). We assessed the association of QRS duration with left ventricular (LV) volume and ejection fraction after anterior MI by using quantitative gated single photon emission computed tomography (SPECT). METHODS: Eighty-two patients with prior anterior MI were enrolled. Intermediate QRS prolongation was defined as QRS duration ≥100 ms without bundle branch block. Quantitative analysis of thallium SPECT was performed on the redistribution image. LV end-diastolic volume (LVEDV), end-systolic volume (LVESV) and ejection fraction (LVEF) were obtained. RESULTS: There were 25 patients with intermediate QRS prolongation and 57 patients with normal QRS duation. Compared to patients with normal QRS duration, patients with intermediate QRS prolongation had larger LVEDV (137.4 ± 75.1 ml vs 87.9 ± 43.6 ml, p = .004), larger LVESV (89.9 ± 69.6 ml vs 49.2 ± 35.5 ml, p = .009) and lower LVEF (39.3 ± 14.6% vs 47.6 ± 12.0%, p = .02). QRS duration was positively associated with LVEDV (r = 0.49, p < .001) and LVESV (r = 0.47, p < .001), and was inversely associated with LVEF (r= -0.32, p < .001). Multivariate analysis showed that male sex (ß = 0.22, p = .04), QRS duration (ß = 0.34, p = .002) and number of abnormal Q waves (ß = 0.37, p < .001) were associated with LVEDV. QRS duration (ß= -0.32, p = .003) and number of abnormal Q waves (ß = -0.40, p < .001) were associated with LVEF. CONCLUSIONS: Our results suggest that QRS duration as well as number of abnormal Q waves is independently associated with LV volume and ejection fraction after anterior MI.

Comparison of 8-frame and 16-frame thallium-201 gated myocardial perfusion SPECT for determining left ventricular systolic and diastolic parameters.

The myocardial perfusion single photon emission computed tomography synchronized with the electrocardiogram (gated SPECT) has been widely used for the assessment of left ventricular (LV) systolic and diastolic functions using Quantitative gated SPECT. The aim of this study was to compare the effects of 8-frame and 16-frame thallium-201 (Tl-201) gated SPECT for determining LV systolic and diastolic parameters. The study population included 42 patients with suspected coronary artery disease who underwent gated SPECT by clinical indication. LV systolic and diastolic parameters were assessed on 8-frame and 16-frame gated SPECT. There were good correlations in end-diastolic volume (r = 0.99, p < 0.001), end-systolic volume (ESV) (r = 0.97, p < 0.001) and ejection fraction (EF) (r = 0.95, p < 0.001) between 8-frame and 16-frame gated SPECT. Bland-Altman plot showed a significant negative slope of -0.08 in EDV indicating a larger difference for larger EDV. Eight-frame gated SPECT overestimated ESV by 2.3 ml, and underestimated EF by -4.2% than 16-frame gated SPECT. There were good correlations in peak filling rate (PFR) (r = 0.87, p < 0.001), one third mean filling rate (r = 0.87, p < 0.001) and time to PFR (r = 0.61, p < 0.001) between 8-frame and 16-frame gated SPECT. Eight-frame gated SPECT underestimated PFR by -0.22 than 16-frame gated SPECT. Eight-frame gated SPECT estimated as much MFR/3 and TPFR as 16-frame gated SPECT. According to the data, the study suggested that 8-frame Tl-201 gated SPECT could underestimate systolic and/or diastolic parameter when compared with 16-frame gated SPECT.

Selvester QRS score and total perfusion deficit calculated by quantitative gated single-photon emission computed tomography in patients with prior anterior myocardial infarction in the coronary intervention era.

Selvester QRS scoring system has an advantage of being inexpensive and easily accessible for estimating myocardial infarct (MI) size. We assessed the correlation and agreement between QRS score and total perfusion deficit (TPD) calculated by quantitative gated single-photon emission computed tomography (QGS) in patients with prior anterior MI undergoing coronary intervention. Sixty-six patients with prior anterior MI and 66 age- and sex-matched control subjects were enrolled. QRS score was obtained using a 50-criteria and 31-point system. QRS score was significantly higher in patients with prior anterior MI than control subjects (12.8 ± 8.9 vs 1.1 ± 2.7 %, p < 0.001). In overall patients (n = 132), QRS score was correlated well with TPD (r = 0.81, p < 0.001). This good correlation was found even in patients with TPD ≤40 % (n = 126) or in patients with TPD ≤30 % (n = 117). In overall patients, MI size estimated by QRS score was 7.0 ± 8.8 %, which was significantly smaller than TPD, 11.4 ± 14.0 % (p < 0.001). Bland-Altman plot showed that there was an increasing difference between QRS score and TPD with increasing MI size. When Blant-Altman plots were applied to patients with TPD ≤40 % and further in patients with TPD ≤30 %, the difference between QRS score and TPD became smaller, and the agreement became better. In overall patients, QRS score was correlated well with QGS measurements, such as end-diastolic volume (r = 0.62, p < 0.001), end-systolic volume (r = 0.67, p < 0.001), or ejection fraction (r = -0.73, p < 0.001). Our results suggest that QRS score reflects TPD well in patients with prior anterior MI, whose TPD is less than approximately 30 % even in the coronary intervention era.

Effects of hemoglobin level on myocardial washout rate of thallium-201 in patients with normal myocardial perfusion assessed by single-photon emission computed tomography.

Myocardial perfusion single-photon emission computed tomography (SPECT) is often performed even in patients with suspected coronary artery disease complicated by anemia. We assessed the effects of hemoglobin level on myocardial washout rate of Thallium-201 (Tl-201) in patients with normal myocardial perfusion assessed by SPECT. The study population consisted of 231 patients with summed stress score of zero on SPECT. The mean myocardial washout rate of Tl-201 in the left ventricle was calculated from the stress and the redistribution Bull's eye map. Hematological test was performed within 2 weeks before gated SPECT. There were 135 male and 96 female patients with a mean age of 72.6 ± 9.0 years. The mean hemoglobin was 12.9 ± 1.9 mg/dl; the median was 13.2 mg/dl and the range was 8.0-16.5 mg/dl. There was a significant inverse correlation between hemoglobin level and myocardial washout rate of Tl-201 (r = -0.45, p < 0.001). Univariate linear regression analysis showed that age, female, body mass index, serum creatinine, hemoglobin, end-diastolic volume, and ejection fraction were associated with myocardial washout rate of Tl-201. Multivariate analysis showed that only hemoglobin was the independent predictor of myocardial washout rate of Tl-201 (ß = -0.35, p < 0.001). Our data suggested that anemia was a major determinant of increased myocardial washout rate of Tl-201 in patients with normal myocardial perfusion on SPECT.

Evaluation of end-tidal CO2 pressure at the anaerobic threshold for detecting and assessing pulmonary hypertension.

Cardiopulmonary exercise testing (CPET) is useful for the evaluation of patients with suspected or confirmed pulmonary hypertension (PH). End-tidal carbon dioxide pressure (PETCO2) during exercise is reduced with elevated pulmonary artery pressure. However, the utility of ventilatory parameters such as CPET for detecting PH remains unclear. We conducted a review in 155 patients who underwent right heart catheterization and CPET. Fifty-nine patients had PH [mean pulmonary arterial pressure (mPAP) ≥25 mmHg]. There was an inverse correlation between PETCO2 at the anaerobic threshold (AT) and mPAP (r = -0.66; P < 0.01). Multiple regression analysis showed that PETCO2 at the AT was independently associated with an elevated mPAP (P = 0.04). The sensitivity and specificity of CPET for PH were 80 and 86%, respectively, when the cut-off value identified by receiver operating characteristic curve analysis for PETCO2 at the AT was ≤34.7 mmHg. A combination of echocardiography and CPET improved the sensitivity in detecting PH without markedly reducing specificity (sensitivity 87%, specificity 85%). Evaluation of PETCO2 at the AT is useful for estimating pulmonary pressure. A combination of CPET and previous screening algorithms for PH may enhance the diagnostic ability of PH.

Use of the augmentation index from applanation tonometry of the radial artery for assessing the extent of coronary artery calcium as assessed by coronary computed tomography.

BACKGROUND: The augmentation index (AI) obtained from applanation tonometry of the radial artery is technically the easiest and quickest of available methods for assessing arterial stiffness. We tested the hypothesis that the radial AI is associated with the extent of coronary artery calcium (CAC) as assessed by coronary computed tomography (CCT). METHODS AND RESULTS: This study included 161 patients with known or suspected coronary artery disease undergoing central hemodynamic measurements and CCT. Radial AI was recorded and was corrected in accordance with heart rate (radial AI@75). Thirty-seven patients had no CAC (CAC score = 0), 85 had low-grade CAC (CAC score = 1-399), and 39 had high-grade CAC (CAC score ≥400). Coronary risk factors, except for age and serum creatinine, were similar among the three groups. There were significant differences in brachial systolic blood pressure (SBP) (p = 0.011) and radial AI@75 (%) (p = 0.006). Multivariate analysis showed that age (ß = 0.27, p = 0.001), serum creatinine (ß = 0.18, p = 0.03), and radial AI@75 (ß = 0.24, p = 0.005) were significantly associated with ln (CAC score + 1), whereas brachial SBP was not. Additionally, serum creatinine (odds ratio: 11.91, 95% confidence interval: 1.46-112.0, p = 0.02) and radial AI@75 (per 10%) (odds ratio: 1.76, 95% confidence interval: 1.22-2.64, p = 0.002) were independent factors associated with high-grade CAC. CONCLUSIONS: Our results suggest that the radial AI is better for estimating CAC than brachial SBP in patients with known or suspected coronary artery disease.