Clinical significance of corrected relative flow reserve derived from 13N-ammonia positron emission tomography combined with coronary computed tomography angiography.

BACKGROUND: This study evaluated corrected relative flow reserve (RFR) derived from 13N-ammonia positron emission tomography (PET) combined with coronary computed tomography angiography (CTA). METHODS: We analyzed 61 patients who underwent coronary CTA, 13N-ammonia PET, and invasive coronary angiography. Triple-vessel disease were excluded. Conventional RFRs were calculated as the ratio of hyperemic myocardial blood flow (hMBF) of hypoperfusion areas to those of non-ischemic lesions. Corrected RFRs were calculated using PET and coronary CTA to adjust coronary territories to their feeding vessels. Diagnostic performance was compared to detect obstructive coronary lesions. RESULTS: Of the 180 vessels analyzed, 50 were diagnosed as obstructive lesions (≥ 70% stenosis and/or fractional flow reserve value ≤ 0.8). The coronary flow reserve (CFR), hMBF, conventional RFR, and corrected RFR of obstructive lesions were significantly lower than those of non-obstructive lesions. In receiver operating characteristic curve analysis, these quantitative PET measurements had area under the curve of 0.67, 0.71, 0.89, and 0.92, respectively. Diagnostic performance differences between corrected and conventional RFR were not statistically significant. CONCLUSION: In patients with single or double vessel disease, indices of RFR, with or without coronary angiographic guidance of the reference coronary territory, are better discriminators of flow-limiting stenoses than hMBF and CFR.

A unique case of ST-elevation myocardial infarction related to very late stent thrombosis.

A 67-year-old man was transferred to our hospital because of anterior ST elevation myocardial infarction (STEMI). He had a history of a sirolimus-eluting stent implantation from the left main to the left anterior descending coronary artery (LAD) 9 years before and had undergone laparoscopic prostatectomy 8 days before in the setting of discontinuation of dual antiplatelet therapy. Emergent coronary angiography showed total occlusion in the distal LAD that was successfully treated by aspiration alone. Optical coherence tomography (OCT) showed no vulnerable lesion from the occluded lesion to the proximal LAD. OCT demonstrated that the thrombus attached to floating struts at the left main bifurcation and non-apposed struts at the left coronary ostium partly protruding to aorta, while the other struts were covered and well-apposed. Based on OCT findings, this case of STEMI was thought to be caused by distal embolism of a thrombus that formed at the stent site before it evolved into total occlusion. .

Beneficial effects of adaptive servo-ventilation therapy on readmission and medical costs in patients with chronic heart failure.

Adaptive servo-ventilation (ASV) therapy is a novel modality of noninvasive positive pressure ventilation and is now widely utilized to treat patients with chronic heart failure (CHF). However, there has been no clinical study of the effect of ASV therapy on readmission and cost-effectiveness for the treatment of CHF. The present study was conducted to evaluate the clinical efficacy and cost-effectiveness of home ASV therapy in 45 patients with a history of two or more admissions a year for worsening CHF. Seven patients refused to undergo chronic ASV therapy and three died. Thus, 35 patients were eventually enrolled in the present study. New York Heart Association class (2.8 ± 0.4 versus 2.3 ± 0.5, p < 0.001), log plasma B-type natriuretic peptide level (2.53 ± 0.44 versus 2.29 ± 0.40 pg/mL, p < 0.0001), left atrial dimension (47.5 ± 7.0 versus 44.9 ± 7.6 mm, p = 0.014), and mitral regurgitation area ratio (20.3 ± 12.1 versus 16.9 ± 8.9%, p = 0.007) decreased significantly after 12 months of ASV therapy. The frequency of hospitalization after ASV was significantly lower than before ASV (1.0 ± 1.0 versus 2.3 ± 0.5 times/year/patient, p < 0.0001). ASV also decreased the duration of hospitalization from 64.4 ± 46.5 to 22.8 ± 27.5 days/year/patient (p < 0.0001). Consequently, the total medical costs were reduced by 37% after ASV (1.95 ± 1.37 versus 3.11 ± 1.75 million yen/patient, p = 0.003). ASV therapy reduced readmissions and medical costs in patients with CHF.

Clinical Usefulness of Coronary Flow Reserve Ratio for the Detection of Significant Coronary Artery Disease on 13N-Ammonia Positron Emission Tomography.

BACKGROUND: This study aimed to evaluate the diagnostic performance of coronary flow reserve (CFR), hyperemic myocardial blood flow (hMBF), and CFR ratio for detecting significant coronary artery disease (CAD) on 13N-ammonia positron emission tomography (PET).Methods and Results:We analyzed 63 patients (mean age, 71±9 years; 43 males) with suspected CAD who underwent both pharmacological stress/rest 13N-ammonia PET and coronary angiography. CFR and hMBF for PET were calculated automatically using quantitative PET software, and the CFR ratio was defined as the ratio of per-vessel CFR to maximum CFR in a standard 17-segment model. We compared the diagnostic performance among the 3 quantitative values. In the per-vessel analysis, 55 vessels were diagnosed as significant CAD (≥70% stenosis and/or fraction flow reserve ≤0.8). CFR, hMBF, and CFR ratio of significant CAD were significantly lower than for non-significant CAD (1.85±0.69 vs. 2.38±0.69; P<0.01, 1.67±0.54 vs. 2.19±0.52 mL·min-1·g-1; P<0.01, and 0.66±0.15 vs. 0.82±0.09; P<0.01, respectively). In the receiver-operating characteristic curve analysis, CFR, hMBF, and CFR ratio had areas under the curve of 0.71, 0.75, and 0.85 respectively, and the CFR ratio was significantly higher than CFR and hMBF (P<0.05). The sensitivity, specificity, and accuracy of the CFR ratio with an optimal cutoff value of 0.75 were 75%, 85%, and 82%, respectively. CONCLUSIONS: Clinically, the CFR ratio in 13N-ammonia PET was more effective in detecting significant CAD.

Favorable effects of early tolvaptan administration in very elderly patients after repeat hospitalizations for acute decompensated heart failure.

Tolvaptan (TLV) is an oral selective vasopressin 2 receptor antagonist that acts on the distal nephrons, causing a loss of electrolyte-free water. To date, its early administration in very elderly patients after repeat hospitalizations for acute decompensated heart failure (ADHF) despite receiving optimal medical therapy has not been evaluated. Fifty-six ADHF patients who were >80 years old and had been repeatedly hospitalized were retrospectively enrolled in this study. Twenty-five patients (14 men; mean age 86.7 ± 5.3 years; control group) received standard therapy and 31 patients (15 men; mean age 85.5 ± 4.5 years; TLV group) received oral TLV within 24 h of admission. The rate of worsening renal function was significantly lower in the TLV group than in the control group (13 vs. 40%, P < 0.05). The duration of the return to body weight at a steady state was significantly shorter in the TLV group (5.3 ± 2.8 days) than in the control group (13.9 ± 9.2 days, P < 0.01). Consequently, the hospitalization period in the TLV group (13.5 ± 5.9 days) was significantly shorter than that in the control group (24.7 ± 12.3 days, P < 0.01). In conclusion, the early administration of TLV to very elderly patients who underwent repeat hospitalizations for ADHF resulted in immediate decongestion and thus reduced the hospitalization period with a lower incidence of worsening renal function.

The feasibility of substituting left atrial wall strain for flow velocity of left atrial appendage.

OBJECTIVE: Non-valvular atrial fibrillation (NVAF) is frequently complicated by thromboembolism. Left atrial appendage (LAA) flow is a predictor of LAA thrombosis. LAA flow is measured by transesophageal echocardiography (TEE), which is a semi-invasive diagnostic tool. Recently, speckle-tracking methods have been adapted for the evaluation of local cardiac function. We hypothesised that if we could determine LAA wall motion utilising a speckle tracking technique, we could non-invasively analyse LAA flow. METHODS: Sixty-three NVAF patients including 38 with chronic atrial fibrillation (CAF), 14 with paroxysmal AF (PAF) and 11 with atrial flutter (AFL) were enrolled in this study. Normal sinus rhythm (NSR) patients with non-thromboembolic cerebral infarction were also included. Immediately after obtaining a 2D movie of the LAA through the aortic oblique short axis view by transthoracic echocardiography, LAA flow velocity was measured by TEE. Mean strains between the posterior and anterior walls were measured using a speckle-tracking technique. RESULTS: Ten patients exhibited a thrombus and 11 had spontaneous echo contrast (SEC) in the auricle. Mean strain value was similar between CAF and PAF, although LAA flow velocity for CAF was significantly reduced compared with PAF (median value 13.7 cm/s versus 36.1 cm/s, p = <.00001). Mean strain of CAF with thrombus/SEC was significantly reduced compared with NSR patients (median value 1.52% versus 3.17%, p = .00181). Furthermore, mean strain was correlated with LAA flow velocity (R = 0.399, R2 = 0.1595, p = .000615). CONCLUSIONS: LAA wall strain identified via speckle-tracking methods may presage LAA peak flow velocity. This technique may contribute to stratification of thrombosis risks in the LAA.

Isolated Left Atrial Infective Mural Endocarditis.

A 52-year-old man presented with a fever and malaise. Transthoracic echocardiogram was performed because of a holosystolic murmur, which showed mitral valve prolapse and a regurgitation jet toward the posterior wall of the left atrium. There was no apparent vegetation at any valves. Blood cultures were positive for Streptococcus mitis/oralis. Transesophageal echocardiogram revealed vegetation only at the posterior wall of the left atrium exposed to the mitral regurgitant jet. We diagnosed this condition as infective mural endocarditis. This case highlighted the need for a detailed observation of the valves and the atrial wall when infective endocarditis is suspected.

Beneficial effects of rapid introduction of adaptive servo-ventilation in the emergency room in patients with acute cardiogenic pulmonary edema.

BACKGROUND: Adaptive servo-ventilation (ASV) at home has been used for patients with chronic heart failure. However, its effect on acute cardiogenic pulmonary edema (ACPE) is not clear. The aim of this study was to elucidate the effect of ASV use in the emergency room in patients with ACPE. METHODS: We enrolled 198 consecutive patients with ACPE. Eighty patients received standard therapies, such as oxygen inhalation and vasodilators (conventional therapy group), and 118 received ASV in addition to standard therapy (ASV therapy group). ASV was initiated in the emergency room immediately after diagnosis. The procedure was switched over from ASV to endotracheal intubation (ETI) when oxygenation was insufficient. RESULTS: The ETI rate in the ASV therapy group was significantly lower than that in the conventional therapy group (3% vs. 21%, p<0.01). The intensive care unit and/or high care unit length of stay in the ASV therapy group was also significantly shorter than that in the conventional therapy group (1.9±2.1 days vs. 5.3±6.8 days, p<0.01). Consequently, the hospitalization period in the ASV therapy group was shorter than that in the conventional therapy group (19.3±11.0 days vs. 26.3±16.6 days, p<0.01). CONCLUSION: In patients with ACPE, rapid introduction of ASV in the emergency room reduces the need for ETI and decreases the hospitalization period.

Contrast-enhanced ultrasound for the evaluation of acute renal infarction.

A 65-year-old male in the dilated phase of hypertrophic cardiomyopathy and with persistent atrial fibrillation was admitted to our hospital because of an episode of ventricular fibrillation following an appropriate shock from an implantable cardiac defibrillator (ICD). At admission, electrocardiography showed a normal sinus rhythm. He had complained of back pain 7 days after the ICD shock. Renal infarction was suspected, although computed tomography and magnetic resonance imaging could not be performed because of chronic renal failure and the presence of his ICD. We, therefore, used contrast-enhanced ultrasonography with a contrast agent to evaluate his acute kidney injury. This showed the left kidney contained a wedge-shaped area that was not enhanced by the contrast agent, indicating an area of infarction.

A calcified amorphous tumor that developed on both sides of the atrioventricular valve annulus.

We report a rare case of a hemodialysis patient with a calcified amorphous tumor (CAT) on both sides of the atrioventricular valve annulus. A 70-year-old female who had received hemodialysis for 23 years because of chronic glomerulonephritis presented to our hospital with acute heart failure. Echocardiography indicated the presence of mobile cardiac masses on the mitral valve and tricuspid valve annulus. We suspected the presence of a cardiac tumor or vegetation. The patient received 3 g/day sulbactam-ampicillin and 60 mg/day gentamicin. Surgery was performed on the 14th day after hospital admission. The patient underwent mitral valve replacement, tricuspid annuloplasty, and tumor resection. Based on the pathological findings, the cardiac tumor was diagnosed as a CAT.

Remote ischemic preconditioning reduces contrast-induced acute kidney injury in patients with ST-elevation myocardial infarction: a randomized controlled trial.

BACKGROUND: Contrast medium-induced acute kidney injury (CI-AKI) is a cardiovascular complication after myocardial infarction treated with emergency percutaneous coronary intervention. The aim of this randomized, sham-controlled trial was to evaluate the impact of remote ischemic preconditioning (RIPC) on CI-AKI in patients with ST-elevation myocardial infarction who received emergency primary percutaneous coronary intervention. METHODS AND RESULTS: Patients with a suspected ST-elevation myocardial infarction were randomly assigned at a 1:1 ratio to receive percutaneous coronary intervention either with (n=63) or without (n=62) RIPC (intermittent arm ischemia through three cycles of 5min of inflation and 5min of deflation of a blood pressure cuff). A total of 47 RIPC patients and 47 control patients met all study criteria. The primary endpoint was the incidence of CI-AKI, which was defined as an increase in serum creatinine >0.5mg/dL or >25% over the baseline value 48-72h after administration of contrast medium. The incidence of CI-AKI was 10% (n=5) in the RIPC group and 36% (n=17) in the control group (p=0.003). The odds ratio of CI-AKI in patients who received RIPC was 0.18 (95% confidence interval: 0.05-0.64; p=0.008). CONCLUSIONS: In patients with ST-elevation myocardial infarction, RIPC before percutaneous coronary intervention reduced the incidence of CI-AKI.

Impact of chronic total coronary occlusion on microvascular reperfusion in patients with a first anterior ST-segment elevation myocardial infarction.

BACKGROUND: We investigated an impact of the presence of chronic total coronary occlusion (CTO) in a non-infarct related coronary artery on microvascular reperfusion in patients with a first anterior ST-segment elevation myocardial infarction (STEMI) who underwent percutaneous coronary intervention (PCI). METHODS: In accordance with the presence or absence of CTO in a non-infarct related coronary artery, we analyzed Thrombolysis in Myocardial Infarction myocardial perfusion (TMP) grade on a scale of 0 to 3, with higher scores indicating better perfusion, and ST-segment resolution in sum of lead I, aVL, and V1 through V6 to evaluate microvascular reperfusion in a total of 140 consecutive patients with a first anterior STEMI. RESULTS: We identified CTO in 15 patients (11% of total). The incidence of impaired microvascular reperfusion was greater in patients with CTO vs without CTO, defined as TMP grades 0 or 1 together with <30% ST-segment resolution (33% vs 6%, respectively; P=.0006) and the enzymatic infarct was larger (10304 ± 8060 IU/L vs 6804 ± 4959 IU/L; P=.009). Logistic regression analysis revealed that CTO is closely associated with incidental impaired microvascular reperfusion (odds ratio, 6.801; 95% confidence interval, 1.284-36.209; P=.024). CONCLUSION: The presence of CTO in a non-infarct related coronary artery might confer a considerable disadvantage upon microvascular reperfusion and result in adverse clinical outcomes of PCI for a first anterior STEMI.

Prognostic utility of T-wave alternans in a real-world population of patients with left ventricular dysfunction: the PREVENT-SCD study.

BACKGROUND: The predictive value of T-wave alternans (TWA) for lethal ventricular tachyarrhythmia in patients with left ventricular (LV) dysfunction is controversial. Also, long-term arrhythmia risk of patients ineligible for the TWA test is unknown. METHODS: This was a multicenter, prospective observational study of patients with LV ejection fraction ≤40% due to ischemic or non-ischemic cardiomyopathies, designed to evaluate the prognostic value of TWA for lethal ventricular tachyarrhythmia. The primary end point was a composite of sudden cardiac death, sustained rapid ventricular tachycardia (VT) or ventricular fibrillation (VF), and appropriate defibrillator therapy for rapid VT or VF. RESULTS: Among 453 patients enrolled in the study, 280 (62%) were eligible for the TWA test. TWA was negative in 82 patients (29%), who accounted for 18% of the total population. The median of follow-up was 36 months. The 3-year event-free rate for the primary end point was significantly higher in TWA-negative patients (97.0%) than in TWA non-negative patients (89.5%, P = 0.037) and those ineligible for the TWA test (84.4%, P = 0.003). Multivariable analysis identified both non-negative TWA [hazard ratio (HR) 4.43; 95% confidence interval (CI) 1.02-19.2; P = 0.047) and ineligibility for the TWA test (HR 6.89; 95% CI 1.59-29.9; P = 0.010) to be independent predictors of the primary end point. CONCLUSIONS: TWA showed high negative predictive ability for lethal ventricular tachyarrhythmia in patients with LV dysfunction, although the TWA-negative patients accounted for only 18% of the entire population. Those ineligible for the TWA test had the highest risk for lethal ventricular tachyarrhythmia.