Effectiveness of Repetitive Hyperbaric Oxygen Therapy for Chronic Limb-Threatening Ischemia

BACKGROUND

Lower extremity artery disease is strongly associated with morbidity and is typically addressed through revascularization interventions. We assessed the clinical outcomes of patients with chronic limb-threatening ischemia (CLTI) without revascularization who did and did not undergo repetitive hyperbaric oxygen therapy (HBOT).

METHODS

Between April 2002 and March 2017, the records of 58 patients with CLTI (Rutherford classification 4 in 19% and 5 in 81%) were evaluated retrospectively. HBOT was performed at 2.8 atm of oxygen (HBOT group). The control group included those who could not continue HBOT and historical controls. Patients in poor general health or with an indication for revascularization therapy were excluded. We examined major adverse events (MAEs) and limb salvage rates. Independent predictors and risk stratification were analyzed using a multivariate regression analysis.

RESULTS

The mean age was 71±13 years. Of all patients, 67% had diabetes and 43% were undergoing hemodialysis. The mean follow-up period was 4.3±0.8 years. The overall survival rate was 84.5% and 81.0% at 1 and 3 years, respectively. The Cox regression analysis indicated that high body mass index (odds ratio [OR]: 0.86; 95% confidence interval [CI]: 0.76-0.97; p=0.01), well-nourished (OR: 1.21; 95% CI: 1.01-1.45), and HBOT (OR: 0.05; 95% CI: 0.01-0.26; p<0.001) independently predicted absence of MAEs. For major limb amputation, the ankle-brachial index (OR: 0.2; 95% CI: 0.05-0.86; p=0.03) and HBOT (OR: 0.04; 95% CI: 0.004-0.32; p=0.003) were independent predictors.

CONCLUSIONS

Repetitive, stand-alone HBOT was associated with MAE-free survival and limb salvage in patients with CLTI.

The effect of mechanical feedback on outcome in self-care support tool based on solution-focused brief therapy

Little is known about the impact of mechanical feedback in self-care support tools. Technically, natural language processing and machine learning can provide mechanical feedback in self-care support tools. This study compared the differences between mechanical feedback and no feedback conditions in a self-care support tool based on solution-focused brief therapy. In the feedback condition, feedback was provided by mechanically determining the probability that the goal answered in goal setting was concrete or realistic.

A total of 501 participants were recruited and randomly assigned to either the feedback (n = 268) or no feedback (n = 233) condition.

The results showed that the mechanical feedback increased the probability of problem-solving. In contrast, solution-building, positive and negative affect, and the probability of living an ideal life increased when using the self-care support tool based on solution-focused brief therapy, regardless of the feedback. In addition, the higher the probability of goal concreteness and reality, the greater the improvement in solution-building and positive affect.

This study suggests that self-care support tools based on solution-focused brief therapy with feedback are more effective than those without feedback. Self-care support tools based on solution-focused brief therapy with feedback can be used as an easily accessible tool to maintain and promote mental health.

Multisensory perceptual distortion including auditory distortions in Alice in Wonderland syndrome: a case report

Alice in Wonderland syndrome (AIWS) is a rare perceptual disorder characterized mainly by perceptual distortions of visual objects and one's own body. While there are many case reports of visual and somatosensory distortions associated with AIWS, little is known about auditory distortion. Therefore, we present the case of a 22-year-old right-handed woman who described having auditory as well as visual and somatosensory distortion experiences and a family history of AIWS. The subject reported experiencing multisensory perceptual distortions, where she sees other people's faces as larger and hears their voices as louder at the same time. This particular case suggests that auditory distortion - which contributes to constructing the perception of the surrounding space and the body - may also be characterized as a perceptual symptom of AIWS.

Clinical utility of 67 Gallium-SPECT/CT for determining osteotomy indication in patients with lower-limb osteomyelitis

Standard non-invasive methods for diagnosing and selecting the best treatment for osteomyelitis in patients with multiple chronic conditions remain to be established. We aimed to evaluate the ability of quantitative ⁶⁷ Ga-citrate single-photon emission computed tomography (⁶⁷ Ga-SPECT/CT) to determine the indication for either non-surgical treatment or osteotomy in patients with lower-limb osteomyelitis (LLOM) associated with diabetes mellitus and lower-extremity ischemia, based on monitoring of inflammatory activity in bone tissue. This single-centre prospective study conducted from January 2012 to July 2017 included 90 consecutive patients with suspected LLOM. Regions of interest were drawn on SPECT images during quantification of Ga accumulation. Subsequently, the inflammation-to-background ratio (IBR) was calculated by dividing the maximal accumulated lesion number by the mean number for the distal femur bone marrow of the unaffected side. Osteotomy was performed in 28 of 90 patients (31%). The osteotomy rate was higher for patients with IBR >8.4 (71.4%) than for those with IBR ≤8.4 (5.5%) (p < 0.001, sensitivity: 0.89, specificity: 0.84). In the multivariate Cox regression analysis, IBR >8.4 was an independent risk factor for osteotomy (hazard ratio [HR]: 19.0, 95% confident interval [CI]: 5.6-63.9, p < 0.001). Transcutaneous oxygen tension (TcPO₂ ) was identified as an independent risk factor for lower-limb amputation (HR: 0.96, 95% CI: 0.92-0.99, p = 0.01). The current results indicate that quantitative ⁶⁷ Ga-SPECT/CT is useful for distinguishing patients with LLOM likely to require osteotomy.

Diagnostic performance of quantitative Ga-SPECT/CT for patients with lower-limb osteomyelitis

BACKGROUND

Patients with lower-limb osteomyelitis (LLOM) may experience major adverse events, such as lower-leg amputations or death; therefore, early diagnosis and risk stratification are essential to improve outcomes. Ga-scintigraphy is commonly used for diagnosing inflammatory diseases. Although the diagnostic performance of planar and SPECT imaging for localized lesions is limited, SPECT/CT, which simultaneously acquires functional and anatomical definition, has resulted in significant improvements to diagnostic confidence. While quantitative Ga-SPECT/CT is an emerging approach to improve diagnoses, its diagnostic performance has not been sufficiently evaluated to date. Therefore, this study aimed to evaluate the diagnostic performance of Ga-SPECT/CT with quantitative analyses for patients with LLOM.

METHODS

A total of 103 consecutive patients suspected of LLOM between April 2012 and October 2016 were analyzed. All patients underwent Ga-scintigraphy with SPECT/CT imaging. Findings were assessed visually, with higher than background accumulation considered positive, and quantitatively, using Ga-SPECT/CT images to calculate the lesion-to-background ratio (LBR), the maximum standardized uptake value (SUVmax), and total lesion uptake (TLU). Diagnoses were confirmed using pathological examinations and patient outcomes, and diagnostic performances of planar, SPECT, and SPECT/CT images were compared. To evaluate prognostic performance, all patients were observed for 5 years for occurrences of major adverse events (MAE), defined as recurrence of osteomyelitis, major leg amputation, or fatal event. Multivariate Cox regression was performed to evaluate outcome factors.

RESULTS

The overall diagnoses indicated that 54 out of 103 patients had LLOM. LBR, SUVmax, and TLU were significantly higher in patients with LLOM (12.23 vs. 1.00, 4.85 vs. 1.34, and 68.77 vs. 8.63, respectively; p < 0.001). Sensitivity and specificity were 91% and 96% for SPECT/CT with LBR, 89% and 94% for SPECT/CT with SUVmax, and 91% and 92% for SPECT/CT with TLU, respectively. MAE occurred in 23 of 54 LLOM patients (43%). TLU was found to be an independent prognostic factor (p = 0.047).

CONCLUSIONS

Ga-SPECT/CT using quantitative parameters, namely LBR and TLU, had better diagnostic and prognostic performances for patients with LLOM compared to conventional imaging. The results suggest that Ga-SPECT/CT is a good alternative for diagnosing LLOM in countries where FDG-PET/CT is not commonly available.

Fear of COVID-19 infection and related factors in Japan: A comparison of college students, pregnant women, hospital nurses and the general public

The fear of COVID-19 has become a social problem during the pandemic. The present study compares the fear of COVID-19 among members of the general public, college students, pregnant women, and hospital nurses. It also examines various factors associated with the fear of COVID-19. In this study, we conducted a survey of the general public on fear of infection and related factors and compared from previous studies of college students, pregnant women, and hospital nurses. A crowdsourced survey was administered to 450 members of the general public, who were asked about their fear of COVID-19 infection. Data from college students, nurses, and pregnant women were recruited from a May-June 2020 survey on fear of COVID-19. An analysis of variance was used to compare the fear of infection among different attribution. The results showed that more pregnant women and fewer college students feared infection, as did equal numbers of hospital nurses and members of the general public. The multiple regression analysis revealed that college students and pregnant women associated the fear of infection with their key source of information, while hospital nurses associated the fear of infection with living with an older person. These results suggest that pregnant women have a significant fear of infection, which is further defined by the risk of serious illness in cases of infection. Although the fear of infection is relatively low among hospital nurses, they fear becoming a source of infection. These results reveal the groups in Japan that fear infection and the reasons for their concern. The present study may help to provide psychological support to counteract the fear of infection in vulnerable groups.

The Association Between COVID-19 Information Sources and Stigma Against Health Care Workers Among College Students: Cross-sectional, Observational Study

Background

The COVID-19 pandemic has triggered stigmatic attitudes against health care workers. Some forms of social media may play a role in disseminating stigmatizing messages.

Objective

We aimed to investigate the association between COVID-19 information sources and stigma against health care workers among college students during the pandemic.

Methods

A cross-sectional, observational study was conducted using a web-based platform in the Tohoku region of Japan. College students aged ≥20 years were asked to complete the questionnaire between August 18 and October 31, 2020. Stigma against health care workers was evaluated using a modified Japanese version of the Social Distance Scale. Participants were also asked to rate their perceived vulnerability to infection using the Japanese version of the Perceived Vulnerability to Disease scale.

Results

A total of 281 students from 8 colleges completed the web-based survey. There were 139 (49.5%) participants who used Twitter, 187 (66.5%) who used news websites, and 46 (16.4%) who used the websites of public health agencies as COVID-19 information sources. After adjusting for age, sex, department, and Perceived Vulnerability to Disease scores, the level of stigma did not differ between students who used Twitter and those who did not. Students who used the websites of public health agencies showed a significantly less stigmatic attitude than those who did not.

Conclusions

Fact-checking and directing visitors to credible information sources from public health agencies may have prevented the formation of stigmatic attitudes toward health care workers. An effective strategy to enable easy access to information provided by public agencies should be integrated into widespread web-based platforms.

The impact of clarifying the long-term solution picture through solution-focused interventions on positive attitude towards life

Solution-focused brief therapy is a psychotherapeutic model. The purpose of this study was to examine the effects of clarity of long-term solutions on positive attitude towards life. In order to examine the effects of the long-term solution image, the conditions for clarifying the long-term and short-term solution images, and not seeking clarification of the solution image were set and randomly assigned. A total of 94 participants who responded to all questions were included in the analysis. The results of this study indicate that clarity of the long-term solution enhances time-oriented attitude. In addition, the clarity of short-term solutions increases the reality of their goals. Furthermore, solution-building and, positive, and ideal levels of life were shown to increase after implementation, regardless of the condition. These results indicate that clarification of the long-term solution expands the positive attitude of valuing limited time.

Depression and anxiety among nursing students during the COVID-19 pandemic in Tohoku region, Japan: A cross-sectional survey

Aim

Restrictions such as physical distancing and online learning for college students were implemented due to the COVID‐19 pandemic. Owing to this, students may experience psychological distress from social isolation and loneliness. Nursing students are subjected to an exacerbated level of distress during the pandemic due to their role as health professionals. Therefore, the present study aimed to investigate the level of anxiety and depression among Japanese nursing students, according to their perceived vulnerability to COVID‐19.

Methods

A total of 281 college students (104 nursing students and 177 other college students) responded to a web‐based anonymous questionnaire survey from 18 August to 31 October 2020. The Hospital Anxiety and Depression Scale was used to evaluate anxiety (HADS‐A) and depression (HADS‐D). Perceived vulnerability to COVID‐19 was assessed using the Perceived Vulnerability to Disease Scale.

Results

In both groups of students, the prevalence of both anxiety (30.5% in nursing students; 69.5% in others) and depressive symptoms (31.1% in nursing students; 68.9% in others) were remarkably high. There were no significant differences in anxiety and depression between nursing and other students after adjusting for perceived vulnerability to COVID‐19 plus socio‐demographic characteristics and stress coping styles. Perceived vulnerability and its interactions with nursing did not show a significant association with either depression or anxiety.

Conclusion

This study highlights the need for greater support and preventive strategies for mental health problems for college students during the COVID‐19 pandemic regardless of perceived vulnerability.

Cardiac Troponin Is Elevated in Patients with Thyrotoxicosis and Decreases as Thyroid Function Improves and Brain Natriuretic Peptide Levels Decrease

INTRODUCTION

High-sensitive cardiac troponin reflects micro-myocardial injury in the absence of overt myocardial infarction.

OBJECTIVE

This study aimed to clarify how thyrotoxicosis affects cardiac troponin.

METHODS

This was a prospective observational study in Japan. Untreated patients with thyrotoxicosis who visited Ito Hospital were enrolled, and medical treatment was initiated for hyperthyroidism. Thyroid function, high-sensitive troponin I (hsTnI), and brain natriuretic peptide (BNP) were measured at baseline and then every 3 months for 1 year.

RESULTS

Data from a total of 143 patients (median age, 42 years; 32 men and 111 women) were investigated. At baseline, median hsTnI was 1.9 pg/mL and ranged from 0 to 69.6 pg/mL. Five patients (3.5%) had a high hsTnI value that exceeded 26.2 pg/mL, which is used as the cutoff for diagnosis of myocardial infarction, and 22 patients (15.4%) had an intermediate value between 5.0 and 26.2 pg/mL. Multivariable regression analysis showed that significant predictors of the hsTnI value were age (β = 0.20, p = 0.01) and BNP (β = 0.43, p < 0.0001) (R² = 0.27, F = 26.0, p < 0.0001), and significant predictors of the BNP value were age (β = 0.23, p = 0.001), hemoglobin (β = -0.43, p < 0.0001), free T₄ (FT₄) (β = 0.23, p = 0.001), and hsTnI (β = 0.27, p < 0.0001) (R² = 0.49, F = 33.8, p < 0.0001). Correlations were found between a decrease in hsTnI and BNP in the first 3 months (ρ = 0.49, p < 0.0001). A decrease in FT₄ in the first 3 months was weakly correlated with decreases in hsTnI (ρ = 0.32, p = 0.0004) and BNP (ρ = 0.32; p = 0.0003). Of the 27 patients with elevated hsTnI (≥5.0 pg/mL), the hsTnI level was normalized in 20 patients within a year.

CONCLUSIONS

In thyrotoxicosis, the myocardial biomarker hsTnI is elevated in about 20% of patients; hsTnI levels decrease as thyroid function improves and BNP decreases.

Beraprost Sodium Protects Against Diabetic Nephropathy in Patients with Arteriosclerosis Obliterans: A Prospective, Randomized, Open-label Study

BACKGROUND

Inhibition of the renin-angiotensin system (RAS) has been used to treat diabetic nephropathy. However, RAS inhibition increases the risk of renal complications. In this study, we evaluated the effect of combining RAS inhibitor treatment with beraprost sodium (BPS), a prostaglandin I2 analog, in diabetic nephropathy with arteriosclerosis obliterans.

METHODS

This study was a prospective, randomized, open-label study. Twenty-six Japanese patients (age >30 years) with diabetic nephropathy and arteriosclerosis obliterans were randomly assigned to the BPS group (n=13), which received the combination of an RAS inhibitor and BPS (120 μg/day) therapy, or the control group (n=13), which received only an RAS inhibitor. Patients were followed up for 1 year. The primary endpoint was the effect of BPS on renal function.

RESULTS

In the control group, serum creatinine (1.64±0.87 to 2.34±1.53 mg/dL, p<0.001), 1/creatinine (0.82±0.47 to 0.65±0.47, p=0.003) cystatin C (1.77±0.61 to 2.18±0.86 mg/L, p<0.001), and the estimated glomerular filtration rate (43.9±26.1 to 34.0±24.6 mL/min/1.73 m(2), p=0.004) were significantly worsened 48 weeks after the start of treatment. Conversely, in the BPS group, serum creatinine (1.71±0.75 to 1.66±0.81 mg/dL, p=0.850), 1/creatinine (0.66±0.19 to 0.71±0.25, p=0.577), cystatin C (1.79±0.55 to 1.80±0.57 mg/L, p=0.999), and the estimated glomerular filtration rate (35.8±10.8 to 38.7±14.4 mL/min/1.73 m(2), p=0.613) were unchanged.

CONCLUSIONS

Combination treatment with BPS and an RAS inhibitor prevented the progression of diabetic nephropathy. These observations should be confirmed in large-scale studies with long-term follow-up.

Imaging Angiogenesis Using 99mTc-Macroaggregated Albumin Scintigraphy in Patients with Peripheral Artery Disease

One problem of vascular angiogenesis therapy is the lack of reliable methods for evaluating blood flow in the microcirculation. We aimed to assess whether (99m)Tc-macroaggregated albumin perfusion scintigraphy ((99m)Tc-MAA) predicts quantitated blood flow after therapeutic angiogenesis in patients with peripheral artery disease.

METHODS

Forty-six patients with peripheral artery disease were treated with bone marrow mononuclear cell implantation (BMCI). Before and 4 wk after BMCI, blood flow was evaluated via transcutaneous oxygen tension (TcPO2), ankle-brachial index, intravenous (99m)Tc-tetrofosmin perfusion scintigraphy ((99m)Tc-TF), and intraaortic (99m)Tc-MAA.

RESULTS

Four weeks after BMCI, TcPO2 improved significantly (20.4 ± 14.4 to 36.0 ± 20.0 mm Hg, P < 0.01), but ankle-brachial index did not (0.65 ± 0.30 to 0.76 ± 0.24, P = 0.07). Improvement in (99m)Tc-TF count (0.60 ± 0.23 to 0.77 ± 0.29 count ratio/pixel, P < 0.01) and (99m)Tc-MAA count (5.21 ± 3.56 to 10.33 ± 7.18 count ratio/pixel, P = 0.02) was observed in the foot region but not the lower limb region, using both methods. When these data were normalized by subtracting the pixel count of the untreated side, the improvements in (99m)Tc-TF count (-0.04 ± 0.26 to 0.08 ± 0.32 count ratio/pixel, P = 0.04) and (99m)Tc-MAA count (1.49 ± 3.64 to 5.59 ± 4.84 count ratio/pixel, P = 0.03) in the foot remained significant. (99m)Tc-MAA indicated that the newly developed arteries were approximately 25 μm in diameter.

CONCLUSION

BMCI induced angiogenesis in the foot, which was detected using (99m)Tc-TF and (99m)Tc-MAA. (99m)Tc-MAA is a useful method to quantitate blood flow, estimate vascular size, and evaluate flow distribution after therapeutic angiogenesis.

Therapeutic vascular angiogenesis for intractable macroangiopathy-related digital ulcer in patients with systemic sclerosis: a pilot study

OBJECTIVE

SSc causes intractable ischaemic ulcers. To avoid major amputation, we examined the safety and efficacy of therapeutic vascular angiogenesis for digital ulcers due to SSc.

METHODS

A single-centre, open-label pilot study was conducted in patients with an ischaemic digital ulcer [n = 40, mean age 65 years (s.d. 8), Rutherford class III-5 or III-6) due to lcSSc (n = 11) or arteriosclerosis obliterans (ASO; n = 29). Bone marrow mononuclear cells (0.4-5.1 × 10(10) cells in total) were administered into the ischaemic limbs. We evaluated short-term safety and efficacy by means of a pain scale, (99m)Tc-tetrofosmin scintigraphy and transcutaneous oxygen tension (TcPO2) before and 4 weeks after treatment. Also, the 2-year outcome was compared.

RESULTS

There was a case of amputation in each group within 4 weeks after therapy. The pain scale significantly decreased in both groups [lcSSc 93 mm (s.d. 9) to 11 (s.d. 16), P < 0.01; ASO 77 mm (s.d. 22) to 16 (s.d. 13), P < 0.01] and TcPO2 significantly improved [lcSSc 9.0 mmHg (s.d. 9) to 35 (s.d. 14), P < 0.01; ASO 18 mmHg (s.d. 10) to 29 (s.d. 21), P < 0.05). At the 2-year follow-up, the limb amputation rate was 9.1% in lcSSc and 20.7% in ASO (P = 0.36), while the recurrence rate was 18.2% in lcSSc and 17.2% in ASO (P = 0.95). All-cause mortality was 27.3% in lcSSc and 17.2% in ASO (P = 0.65).

CONCLUSION

In patients with lcSSc, bone marrow mononuclear cell implantation provides clinical benefit and is safe, without major adverse reactions, and may become an effective strategy.

TRIAL REGISTRATION

UMIN-CTR, http://www.umin.ac.jp/ctr/index-j.htm, no. UMIN000004112.

Usefulness of rosuvastatin to prevent periprocedural myocardial injury in patients undergoing elective coronary intervention

The aim of the present study was to investigate whether percutaneous coronary intervention-related periprocedural myocardial infarction (MI) can be suppressed more significantly with high- compared with low-dose rosuvastatin. A total of 232 patients scheduled to undergo elective percutaneous coronary intervention within 5 to 7 days were assigned to groups that would receive either 2.5 or 20 mg/day of rosuvastatin (n = 116 each). The incidence of periprocedural MI did not significantly differ between the high and low-dose groups (8.7% vs 18.7%, p = 0.052). In patients who were not taking statins at the time of enrollment, high-dose rosuvastatin significantly suppressed periprocedural MI compared with the low dose (10.5% vs 30.0%, p = 0.037). The difference was not significant in patients who were already taking statins (high vs low dose 7.6% vs 10.6%, p = 0.582). In conclusion, the incidence of percutaneous coronary intervention-related periprocedural MI was reduced more effectively by high-dose than by low-dose rosuvastatin in statin-naive patients. However, low-dose rosuvastatin is sufficient for patients who are already taking statins.

The dipeptidyl peptidase-4 inhibitor sitagliptin improves vascular endothelial function in type 2 diabetes

The vascular endothelial function is impaired in the very early stage of atherosclerosis in diabetic patients. The goal of this study was to identify the mechanism underlying the improvement in vascular endothelial function by sitagliptin in type 2 diabetes mellitus patients. This study was an open-labeled prospective observational single arm trial. Forty patients were treated with 50 mg of sitagliptin once daily for 12-weeks. The flow-mediated dilation (FMD) and plasma adiponectin were measured at baseline and 12 weeks after initiating treatment. The %FMD was significantly increased after treatment (4.13 ± 1.59 vs 5.12 ± 1.55, P < 0.001), whereas the nitroglycerin-mediated dilation (NMD) did not change. The plasma adiponectin levels significantly increased (13.0 ± 11.3 vs 14.3 ± 12.8, P < 0.001). The changes in the FMD were significantly correlated with those of the plasma adiponectin (r = 0.322, P < 0.05). A multivariate linear regression analysis demonstrated that the improvement in the FMD is associated with the plasma adiponectin (P < 0.05). The treatment of type 2 diabetes mellitus patients with sitagliptin reverses vascular endothelial dysfunction, as evidenced by increase in the FMD, and improvement of the adiponectin levels.

Disruption of atherosclerotic neointima seven years after bare metal stent deployment

A 58-year-old male with a history of prior myocardial infarction, hypertension, and dyslipidemia was admitted due to deteriorating exertional angina. A bare metal stent (Multilink plus™, GUIDANT Corporation, Santa Clara, CA, USA) had been implanted into the proximal left anterior descending artery because of ST-elevation myocardial infarction 7 years earlier. Optical coherence tomography (OCT) showed a disruption of the atherosclerotic neointima overlying the stent. Intravascular imaging studies and pathological studies have shown that neointima within a bare-metal stent often transform into atherosclerotic tissue during an extended period of time. In the current report, OCT demonstrated that a disruption of the atherosclerotic neointima has the potential to cause the development of unstable clinical features. OCT examinations therefore help to understand the pathogenesis of acute coronary syndrome after stent implantation.

Prediction of limb salvage after therapeutic angiogenesis by autologous bone marrow cell implantation in patients with critical limb ischemia

PURPOSE

Despite advances in therapeutic angiogenesis by bone marrow cell implantation (BMCI), limb amputation remains a major unfavorable outcome in patients with critical limb ischemia (CLI). We sought to identify predictor(s) of limb salvage in CLI patients who received BMCI.

MATERIALS AND METHODS

Nineteen patients with CLI who treated by BMCI were divided into two groups; four patients with above-the-ankle amputation by 12 weeks after BMCI (amputation group) and the remaining 15 patients without (salvage group). We performed several blood-flow examinations before BMCI. Ankle-brachial index (ABI) was measured with the standard method. Transcutaneous oxygen tension (TcPO2) was measured at the dorsum of the foot, in the absence (baseline) and presence (maximum TcPO2) of oxygen inhalation. (99m)technetium-tetrofosmin ((99m)Tc-TF) perfusion index was determined at the foot and lower leg as the ratio of brain.

RESULTS

Maximum TcPO2 (p = 0.031) and (99m)Tc-TF perfusion index in the foot (p = 0.0068) was significantly higher in the salvage group than in the amputation group. Receiver operating characteristic (ROC) curve analysis identified maximum TcPO2 and (99m)Tc-TF perfusion index in the foot as having high predictive accuracy for limb salvage.

CONCLUSION

Maximum TcPO2 and (99m)Tc-TF perfusion index in the foot are promising predictors of limb salvage after BMCI in CLI.

Angioscopic study of silent plaque disruption in nonischemic related coronary artery in patients with stable ischemic heart disease

Plaque disruption, which may be associated with some coronary risk factors, plays a key role in the development of acute coronary syndromes and progression of atherosclerosis. However, the clinical profile of asymptomatic plaque disruption in stable ischemic heart disease has not been well evaluated. The aim of the present study was to investigate the frequency and determinants of silent plaque disruption (SPD) in patients with stable ischemic heart disease using coronary angioscopy. Forty-one patients with stable angina or old myocardial infarction (OMI) without any complaints within 3 months were included in the present study. Angioscopy was successfully performed through 49 nonischemic related coronary arteries. The presence of SPD and coronary risk factors were recorded. Silent plaque disruption was found in 12 patients with stable ischemic heart disease (12/41, 29.3%), and the frequency of SPD in nonischemic related coronary arteries was 26.5% (13/49). A significantly higher frequency of SPD was noted in yellow plaques than in white plaques (35.3% versus 6.7%, P = 0.043). Overall, the independent clinical risk factors of SPD in nonischemic related coronary arteries were diabetes mellitus (P = 0.018; OR, 18.8209; 95% CI, 1.6525 to 214.3523) and hypertension (P = 0.0313; OR, 6.6485; 95% CI, 1.1850 to 37.3019). These results suggest silent plaque disruption was commonly observed in nonischemic related coronary arteries in patients with stable ischemic heart disease and its determinants were diabetes mellitus and hypertension.

Coronary perforation during percutaneous coronary intervention

Coronary perforation is an undesirable complication during percutaneous coronary intervention (PCI). We reviewed the cases of overt coronary perforation in our institute and analyzed their clinical backgrounds, the characteristics of the target lesion, management, and clinical outcomes. Between 1991 and 2005, we experienced 12 cases (0.35%) of coronary perforation in a total of 3415 PCI procedures. The perforation occurred during the use of debulking devices in 3 cases, immediately after stenting in 2, immediately after postdilatation of the stent in 2, and during wiring in 3 cases. Restoration was attempted by long inflation of a balloon in 7 cases, implantation of a covered stent graft in 1, and emergency surgical repair in 1 case. Subsequent cardiac tamponade occurred in 3 patients who required pericardiocentesis, and 1 patient died due to congestive heart failure. Administration of protamine was effective in stopping the bleeding in 6 patients, whereas continuation of antiplatelet therapy resulted in no overt rebleeding. Coronary perforation during PCI is a rare complication but is associated with significant morbidity and mortality. Intravenous administration of protamine is effective when it is used in conjunction with nonsurgical devices for initial management of perforation.

Transduction of the anti-apoptotic PTD-FNK protein improves the efficiency of transplantation of bone marrow mononuclear cells

Since most transplanted cells rapidly die in an ischemic environment by hypoxia and hyponutrition, it is crucial to know how to protect transplanted cells for improving transplantation efficiency. We examined whether the transduction of an artificial anti-cell death protein (PTD-FNK) into bone marrow mononuclear cells (BM-MNCs) prevents cell death and improves the transplantation efficiency of BM-MNCs in ischemic regions. Rat bone marrow cells were prepared from the femur and tibia and cultured on dishes precoated with human fibronectin in the absence of serum. BM-MNCs transduced with PTD-FNK survived better than those without the protein (P<0.008) and retained the potential to differentiate into endothelial progenitor cells (EPCs), as judged by the uptake of an acetylated low-density lipoprotein and the ability to bind lectin. Next, we used a co-culture system comprising human umbilical vein endothelial cells (HUVECs) and fibroblasts to examine angiogenic potential. HUVECs pretreated with PTD-FNK survived and formed a blood-vessel-like structure better than untreated cells (P<0.001). When BM-MNCs expressing EGFP were transplanted into ischemic areas of a male rat ischemic hindlimb model, the cells pretreated with PTD-FNK were incorporated into blood vessel with a higher efficiency than the untreated BM-MNCs (P=0.03). BM-MNCs protected through transduction of PTD-FNK maintained their angiogenic potential. Thus, PTD-FNK improves the transplantation efficiency of BM-MNCs into ischemic regions.

Chronic direct stimulation of adenylyl cyclase induces cardiac desensitization to catecholamine and beta-adrenergic receptor downregulation in rabbits

Chronic stimulation of beta-adrenergic receptors (betaARs) induces betaAR downregulation. However, it is not known whether continuous activation of adenylyl cyclase without direct stimulation of betaARs leads to receptor downregulation. This study investigated the effects of chronic stimulation of adenylyl cyclase with colforsin, on hemodynamic variables, and on myocardial betaAR density. In all, 55 rabbits received intravenous colforsin (1.6 microg/kg/min, n = 20), isoproterenol (ISO; 0.4 microg/kg/min, n = 16), or saline (n = 19) for two weeks. After chronic drug administration, responses of systolic (Delta% peak LV +dP/dt) and diastolic function (Delta% peak LV -dP/dt), and heart rate (Delta% heart rate), to acute administration of ISO (0.05 to 0.2 microg/kg/min) or colforsin (5 to 20 nmol/kg/min) were decreased compared to those before chronic administration. betaAR density in the colforsin group (69.8 +/- 13.8 fmol/ml protein) was less than that in the saline group (79.8 +/- 15.0 fmol/ml protein, P < 0.05), but was greater than that in the ISO group (56.3 +/- 8.4 fmol/ml protein, P < 0.05). Thus, chronic direct stimulation of adenylyl cyclase elicited systolic and diastolic functional desensitization to betaAR stimulation or adenylyl cyclase stimulation, and myocardial betaAR downregulation.

Therapeutic angiogenesis by autologous bone marrow cell implantation for refractory chronic peripheral arterial disease using assessment of neovascularization by 99mTc-tetrofosmin (TF) perfusion scintigraphy

We investigated efficacy and safety of implantation of autologous bone marrow mononuclear cells plus platelets, including endothelial progenitor cells (EPCs), for recovering refractory chronic peripheral arterial disease (PAD) using visual and quantitative analyses by 99mTc-tetrofosmin (TF) perfusion scintigraphy, and also investigated various quantitative assessments objectively. We performed 12 consecutive cases and 19 limbs and hands with severe chronic PAD that were almost Fontaine class IV (11/12 cases, about 92%) in this trial. This treatment was very effective in relieving severe pain of PAD, especially for Buerger's disease. We used a visual analog scale (VAS) for measurement of pain level. The maximum pain level before implantation was 66.5+/-5.0 mm, and it decreased to 12.1+/-2.2 mm after implantation (p < 0.001). Rest pain in legs and fingers was resolved in 11 cases (11/12 cases, 92%). All patients could measure pain-free walking time on a treadmill, which improved remarkably (140+/-53 s before implantation vs. 451+/-74 s after implantation, p = 0.034). Resting ankle brachial pressure index (ABI) in legs implanted with bone marrow mononuclear cells was also improved (0.65+/-0.08 before implantation vs. 0.73+/-0.07 after implantation, p = 0.055). According to 99mTc-TF perfusion scintigraphy, the proximal area (region from knee to ankle) was 1.32+/-0.10 before implantation versus 1.56+/-0.11 after implantation (p = 0.007). 99Tc-TF perfusion scintigraphy in the distal area (region from ankle to end of toes, or from wrist to end of fingers) was 0.79+/-0.06 before implantation versus 0.83+/-0.06 after implantation (p = 0.29). Ischemic legs and hands that were injected showed increased perfusion blood flow. 99mTc-TF perfusion scintigraphy was effective to estimate visual and quantitative analysis of collateral vessels in neovascularization. We were successful with this new treatment for the most severe, chronic PAD that was not curable by any of the current treatments. Thus, this therapeutic angiogenesis could be a new strategy for saving severe ischemic limbs and hands.

Propranolol prevents enhanced stress signaling in Gs alpha cardiomyopathy: potential mechanism for beta-blockade in heart failure

Beta-adrenergic receptor (beta-AR) blockade is now widely utilized therapeutically for heart failure, but its cellular mechanism of action is not clear. Mice with cardiac-specific overexpressed Gs alpha develop cardiomyopathy with age, which can be prevented by beta-AR blockade, making this model potentially useful for addressing this question. Our hypothesis was that distal mechanisms in beta-AR signaling, i.e. mitogen-activated protein kinases, were a potential mechanism. At 6-9 months, when cardiomyopathy began to develop in Gs alpha mice, there were significant increases in phospho-kinase levels of p38 MAP kinase (p38 MAPK), and p70(S6K) compared to wild type. In contrast, phospho-kinase levels of ERK and Akt were increased at 9-10 months, but phospho-kinase levels of c-Jun N-terminal kinase (JNK) increased only at 15-20 months (when cardiomyopathy was fully manifest). Treatment of 9-10 months old Gs alpha mice with propranolol for 5 weeks reverted the phospho-kinase levels of these kinases known to be involved in the growth and death of cardiac myocytes. Another novel observation of this study was that there were also decreases in total protein levels of p38 MAPK, p70(S6K), JNK, and Akt following beta-AR blockade. Thus, chronically enhanced beta-AR signaling elicits a differential pattern of altered mitogen-activated protein kinases, which was reversed with beta-AR blockade, raising the possibility that the beneficial effects of beta-AR blockade therapy in heart failure may be due in part to the inhibition of these pathways.

Neurally-mediated increase in calcineurin activity regulates cardiac contractile function in absence of hypertrophy

OBJECTIVE

The calcineurin pathway has been involved in the development of cardiac hypertrophy, yet it remains unknown whether calcineurin activity can be regulated in myocardium independently from hypertrophy and cardiac load.

METHODS

To test that hypothesis, we measured calcineurin activity in a rat model of infrarenal aortic constriction (IR), which affects neurohormonal pathways without increasing cardiac afterload.

RESULTS

In this model, there was no change in arterial pressure over the 4-week experimental period, and the left ventricle/body weight ratio did not increase. At 2 weeks after IR, calcineurin activity was increased 1.8-fold (P<0.05) and remained elevated at 4 weeks (1.7-fold, P<0.05). Similarly, the cardiac activity of calcium calmodulin kinase II (CaMKII) was increased significantly after IR, which confirms a regulation of Ca(2+)-dependent enzymes in this model. In cardiac myocytes, the increased activity of calcineurin was accompanied by a significant decrease in L-type Ca(2+) channel activity (I(Ca)) and contraction velocity (-dL/dt). Cardiac denervation prevented the activation of calcineurin after IR, which demonstrates that a neurohormonal mechanism is responsible for the changes in enzymatic activity. In addition, cardiac denervation suppressed the effects of IR on I(Ca) and -dL/dt, which shows that calcineurin activation is related to altered contractility. However, action potential duration, the densities of inward rectifier K(+) currents (I(K1)), and outward K(+) currents (I(to) and I(K)) were not altered in IR myocytes.

CONCLUSIONS

Calcineurin can be activated in the heart through a neural stimulus, which induces alterations in Ca(2+) currents and contractility. These effects occur in the absence of myocyte hypertrophy, electrophysiological changes in action potential, and K(+) channel currents.

Effects of Statins on Circulating Oxidized Low-density Lipoprotein in Patients With Hypercholesterolemia

Recently, it has been reported that circulating oxidized low-density lipoprotein (Ox-LDL) might be a pivotal indicator for coronary artery disease and the severity of acute coronary syndromes. The purpose of this study was to investigate the effects of statins on Ox-LDL in patients with hypercholesterolemia. Sixteen patients with hypercholesterolemia were randomly assigned to 2 groups, one received 10 mg of pravastatin (n = 8) and the other received 20 mg of fluvastatin (n = 8). The plasma level of Ox-LDL was measured using a newly developed sandwich enzyme-linked immunosorbent assay (ELISA) method. There were no differences between the two groups in Ox-LDL, total cholesterol (TC), or LDL cholesterol (LDL-C) at the baseline. The reduction in Ox-LDL in the fluvastatin group was significantly higher than that in the pravastatin group (47.5% versus 25.2%, P = 0.033). The reductions in TC and LDL-C did not differ between the two groups.

CONCLUSION

The present study has shown for the first time that the level of circulating Ox-LDL was significantly decreased by treatment with statins. In addition, the lowering effect of statins on the circulating Ox-LDL was independent of their lipid-lowering effect. Fluvastatin was more effective than pravastatin with regard to decreasing the circulating Ox-LDL.

Common genomic response in different mouse models of beta-adrenergic-induced cardiomyopathy

BACKGROUND

Although beta-adrenergic receptor (AR) blockade therapy is beneficial in the treatment of heart failure, little is known regarding the transcriptional mechanisms underlying this salutary action.

METHODS AND RESULTS

In the present study, we screened mice overexpressing Gsalpha, beta1AR, beta2AR, or protein kinase A to test if a common genomic pathway exists in different models with enhanced beta-adrenergic signaling. In mice overexpressing Gsalpha, differentially expressed genes were identified by mRNA profiling. In addition to well-known markers of cardiac hypertrophy (atrial natriuretic factor, CARP, and beta-myosin heavy chain), uncoupling protein 2 (UCP2), a protein involved in the control of mitochondrial membrane potential, and four-and-a-half LIM domain protein-1 (FHL1), a member of the LIM protein family, were predicted to be upregulated. Upregulation of these genes was confirmed by quantitative reverse transcriptase-polymerase chain reaction at all time points tested during the development of cardiomyopathy in mice overexpressing Gsalpha. In mice overexpressing beta1AR, beta2AR, or protein kinase A, increased UCP2 and FHL1 expression was also observed at the onset of cardiomyopathy. BetaAR blockade treatment reversed the cardiomyopathy and suppressed the increased expression of UCP2 and FHL1 in mice overexpressing Gsalpha.

CONCLUSIONS

UCP2 and FHL1 are important candidate genes that correlate with the development of betaAR-induced cardiomyopathy in different mouse models with enhanced betaAR signaling. In addition to preserving cardiac function, betaAR blockade treatment also prevents the genomic regulation that correlates with the onset of heart failure.

Type 5 adenylyl cyclase disruption alters not only sympathetic but also parasympathetic and calcium-mediated cardiac regulation

In a genetically engineered mouse line with disruption of type 5 adenylyl cyclase (AC5-/-), a major cardiac isoform, there was no compensatory increase in other isoforms of AC in the heart. Both basal and isoproterenol (ISO)-stimulated AC activities were decreased by 30% to 40% in cardiac membranes. The reduced AC activity did not affect cardiac function (left ventricular ejection fraction [LVEF]) at baseline. However, increases in LVEF after ISO were significantly attenuated in AC5-/- (P<0.05, n=11). Paradoxically, conscious AC5-/- mice had a higher heart rate compared with wild-type (WT) mice (613+/-8 versus 523+/-11 bpm, P<0.01, n=14 to 15). Muscarinic agonists decreased AC activity, LVEF, and heart rate more in WT than in AC5-/-. In addition, baroreflex-mediated, ie, neuronally regulated, bradycardia after phenylephrine was also attenuated in AC5-/-. The carbachol-activated outward potassium current (at -40 mV) normalized to cell capacitance in AC5-/- (2.6+/-0.4 pA/pF, n=16) was similar to WT (2.9+/-0.3 pA/pF, n=27), but calcium (Ca2+)-mediated inhibition of AC activity and Ca2+ channel function were diminished in AC5-/-. Thus, AC5-/- attenuates sympathetic responsiveness and also impairs parasympathetic and Ca2+-mediated regulation of the heart, indicating that those actions are not only regulated at the level of the receptor and G-protein but also at the level of type 5 AC.

Disruption of type 5 adenylyl cyclase gene preserves cardiac function against pressure overload

The sympathetic nervous system is designed to respond to stress. Adenylyl cyclase (AC) is the keystone of sympathetic transmission, yet its role in response to acute overload in the heart or in the pathogenesis of heart failure is controversial. We examined the effects of pressure overload, induced by thoracic aortic banding, in mice in which type 5 AC, a major cardiac AC isoform, was disrupted (AC5-/-). Left ventricular weight/tibial length ratio (LVW/TL) was not different between the WT and AC5-/- at baseline and increased progressively and similarly in both groups at 1 and 3 wk after aortic banding. However, LV ejection fraction (LVEF) fell in WT at 3 wk after banding (from 70 +/- 2.8 to 57 +/- 3.9%, P < 0.05), and this decrease was associated with LV dilatation, indicating incipient cardiac failure. In contrast, AC5-/- mice did not exhibit a fall in LVEF from 74 +/- 2.2%. The number of apoptotic myocytes was similar at baseline, but it increased roughly 4-fold in WT at both 1 and 3 wk after banding, and significantly less, P < 0.05, in AC5-/-. Importantly, the increase in apoptosis occurred before the decline in LVEF in WT. The protective mechanism seems to involve Bcl-2, which was up-regulated significantly more in AC5-/- mice with pressure overload. Our findings suggest that limiting type 5 AC plays a protective role in response to pressure overload and the development of heart failure, potentially through limiting the incidence of myocardial apoptosis.

Gender differences on the effects of aging on cardiac and peripheral adrenergic stimulation in old conscious monkeys

We examined the effects of gender and aging on cardiac and peripheral hemodynamic responses to beta-adrenergic receptor (beta-AR) stimulation in young (male = 5.9 +/- 0.4 yr old and female = 6.5 +/- 0.7 yr old) and old (male = 19.8 +/- 0.7 yr old and female = 21.2 +/- 0.2 yr old) conscious monkeys (Macaca fascicularis), chronically instrumented for measurements of left ventricular (LV) and arterial pressures as well as cardiac output. Baseline LV pressure, the first derivative of LV pressure (LV dP/dt), cardiac index, mean arterial pressure, total peripheral resistance (TPR), and heart rate in conscious monkeys were not different among the four groups. Increases in LV dP/dt in response to 0.1 microg/kg isoproterenol (Iso) were diminished (P < 0.05) in old males (+99 +/- 11%) compared with young males (+194 +/- 18%). In addition, the inotropic responses to norepinephrine (NE) and forskolin (FSK) were significantly depressed (P < 0.05) in old males. Iso-induced reductions of TPR were less (P < 0.05) in old males (-28 +/- 2%) than in young males (-49 +/- 2%). The changes of TPR in response to NE and FSK were also significantly attenuated (P < 0.05) in old males. However, the LV dP/dt responses to BAY y 5959 (15 microg. kg-1. min-1), a Ca2+ channel promotor independent of beta-AR signaling, were not significantly different between old and young males. In contrast to results in male monkeys, LV dP/dt and TPR responses to Iso, NE, and FSK in old females were similar to those observed in young females. Thus both cardiac contractile and peripheral vascular dynamic responses to beta-AR stimulation are preserved in old female but not old male monkeys. This may explain, in part, the reduced cardiovascular risk in the older female population.

Adding angiotensin II type 1 receptor blockade to angiotensin-converting enzyme inhibition limits myocyte remodeling after myocardial infarction

BACKGROUND

Adding angiotensin II type 1 receptor blockade (ARB) to angiotensin-converting enzyme inhibition (ACEI) further attenuates left ventricular (LV) remodeling in an ovine model of myocardial infarction (MI). We hypothesized that combined therapy with ACEI and ARB (CT) would be additive in the limitation of the myocyte hypertrophy and dysfunction that occurs in untreated adjacent noninfarcted regions during remodeling.

METHODS AND RESULTS

Nineteen sheep underwent coronary ligation to create a moderate-sized anteroapical infarction. Post-MI day 2, sheep were randomized to therapy with ramipril (ACEI, n = 5) or ramipril plus losartan (CT, n = 6) or none (untreated, n = 8). Infarct size was similar between groups. At 8 weeks post-MI, myocytes were isolated from regions adjacent to and remote from the infarct to measure morphometric indices (cell volume, length, cross-sectional area, width) and parameters of contraction (% shortening and -dL/dt, rate of shortening) and relaxation (+dL/dt [rate of relengthening] and TR 70% [time for 70% relengthening]). Volume % collagen was measured from adjacent and remote regions. Adjacent myocyte volume was different between groups (2.5 +/- 0.1 x 10(4) microm(3) in CT, 3.0 +/- 0.4 x 10(4) microm(3) in ACEI, 3.5 +/- 0.2 x 10(4) microm(3) in untreated, analysis of variance [ANOVA] P =.001) as was length (158 +/- 4 microm, 161 +/- 9 microm, 189 +/- 8 microm, respectively, ANOVA P <.001). Adjacent cell volume and length in CT were lower than untreated (P <.05). Percent shortening and -dL/dt of isolated adjacent myocytes were improved with both ACEI (7.9 +/- 0.3%, -131 +/- 6 microm/sec, P <.05) and CT (7.7 +/- 0.3%, -144 +/- 8 microm/sec, P <.05) compared with no therapy (6.4 +/- 0.4%, -104 +/- 7 microm/sec), as was both +dL/dt and TR 70%. No between-group difference in volume % collagen was found in adjacent or remote regions.

CONCLUSION

Compared with ACEI alone, the addition of ARB further limits adjacent noninfarcted myocyte hypertrophy during post-MI LV remodeling. Both ACEI alone and CT preserve isolated unloaded myocyte function, but neither significantly reduce interstitial collagen. The additional benefit of ARB on regional and global function in vivo may also be due to other factors including regional load.