Myocardial flow reserve recovery in patients with Takotsubo syndrome: Insights from positron emission tomography.

BACKGROUND: Coronary microvascular dysfunction (CMD) has been implicated in the pathogenesis of Takotsubo syndrome (TTS). Positron emission tomography (PET) plays a key role in the assessment of CMD through myocardial flow reserve (MFR). However, there is limited information on the temporal progression of MFR and its relationship to coronary artery disease (CAD) in TTS patients. METHODS: This study evaluated patients with TTS who underwent cardiac catheterization and PET within one year of hospitalization. Patients were categorized into acute (≤10 days), subacute (11-30 days), and chronic (≥31 days) stages based on post-onset time of PET assessment. MFR values and prevalence of abnormal MFR (<2.0) were compared between stages. Temporal MFR changes in patients with obstructive CAD (≥70% stenosis by coronary angiography), non-obstructive CAD, and normal coronaries were compared. RESULTS: Of the 88 patients studied (mean age 70; 96% female), 52 (59%) were in the acute, 17 (19%) in the subacute, and 19 (22%) in the chronic stage. Median MFR in the acute stage was 2.0 (1.5-2.3), with 58% of patients showing abnormal MFR. A significant time-dependent improvement in MFR was observed (P = 0.002), accompanied by a decreased prevalence of abnormal MFR (P = 0.016). While patients with normal coronaries showed significant MFR improvement over time (P = 0.045), patients with obstructive or non-obstructive CAD demonstrated no improvement across three stages (P = 0.346 and 0.174, respectively). CONCLUSION: PET-derived MFR was impaired in TTS patients during the acute phase, with improvement suggesting potential recovery from CMD over time. The concurrent presence of obstructive CAD might impede this recovery process.

Utility of FFRCT in Patients with Chest Pain.

PURPOSE OF REVIEW: The goal of this article is to review the data supporting the use of fractional flow reserve derived from coronary computed tomography angiography (FFRCT) in patients with chest pain. REVIEW FINDINGS: Numerous clinical trials have demonstrated that the diagnostic accuracy of coronary computed tomography angiography (CCTA) can be improved with the use of FFRCT, primarily due to its superior specificity when compared to CCTA alone. This promising development may help reduce the need for invasive angiography in patients presenting with chest pain. Furthermore, some studies have indicated that incorporating FFRCT into decision-making is safe, with an FFRCT value of ≥ 0.8 being associated with favorable outcomes. While FFRCT has been shown to be feasible in patients with acute chest pain, further large-scale studies are warranted to confirm its utility. The emergence of FFRCT as a tool for the management of patients with chest pain is promising. However, potential limitations require the interpretation of FFRCT in conjunction with clinical context.

Serial changes in cardiac sympathetic nervous function after transcatheter aortic valve replacement: A prospective observational study using 123I-meta-iodobenzylguanidine imaging.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) can rapidly improve cardiac sympathetic nervous function (CSNF) within 2 weeks in patients with aortic stenosis (AS). However, whether such short-term improvements will be sustained thereafter remains unclear. METHODS: Patients with severe AS who underwent TAVR between October 2017 and June 2019 were enrolled in this single-center, prospective, observational study. 123I-meta-iodobenzylguanidine imaging was performed at baseline, within 2 weeks after TAVR, and at 6 to 12 months post-TAVR to evaluate the heart-mediastinum ratio (H/M) and washout rate. RESULTS: Of 183 consecutive patients, 75 (19 men; median age: 86 years) were evaluated. The late H/M significantly improved within 2 weeks after TAVR (P = .041) and further improved over 6 to 12 months after TAVR (P = .041). Multivariate analysis revealed that the baseline mean aortic valve pressure gradient (mPG) was an independent predictor of mid-term improvement in the late H/M (> 0.1) (P = .037). Patients with a high baseline mPG (≥ 58 mmHg) exhibited a significantly greater increase in the late H/M than those with a low baseline mPG (< 42 mmHg) (0.24 vs 0.01; P = .029). CONCLUSION: CSNF demonstrated sustained improvement from within 2 weeks after TAVR until 6 to 12 months later. Such improvement was related to baseline hemodynamic AS severity.

Early effects of transcatheter aortic valve replacement on cardiac sympathetic nervous function assessed by 123I-metaiodobenzylguanidine scintigraphy in patients with severe aortic valve stenosis.

PURPOSE: The effects of transcatheter aortic valve replacement (TAVR) on cardiac sympathetic nervous (CSN) function have not been fully explored. This study aimed to investigate the early (within 2 weeks) effects of TAVR on CSN function in patients with severe aortic valve stenosis (AS) using 123I-metaiodobenzylguanidine (MIBG) scintigraphy. METHODS: Of 143 consecutive patients who were scheduled to undergo TAVR, 67 (18 men; median age 86 years) were evaluated in this single-centre prospective observational study. MIBG scintigraphy was performed at baseline and 3-14 days after the TAVR procedure to evaluate the heart-mediastinum ratio (H/M) and washout rate (WR). Differences between baseline and post-TAVR MIBG parameters were analysed. MIBG parameter changes were compared with echocardiographic parameters. Furthermore, factors involved in the improvement in MIBG parameters were investigated. RESULTS: All patients successfully underwent TAVR with improved echocardiographic parameters, including aortic valve area (AVA; 0.6 cm2 vs. 1.6 cm2), peak velocity (4.5 m/s vs. 2.0 m/s), mean pressure gradient (50 mmHg vs. 9 mmHg), and left ventricular ejection fraction (56% vs. 62%) (all p < 0.001). On MIBG imaging, delayed H/M significantly increased (2.57 vs. 2.68, p < 0.001), whereas WR decreased (32.2% vs. 26.8%, p < 0.001). In multivariate analysis, higher baseline WR was associated with improvement in WR (> 3%). Female sex, Clinical Frailty Scale score ≤ 5, baseline estimated glomerular filtration rate, and baseline AVA were predictors of improvement in delayed H/M (> 0.1). Baseline AVA and E/E' were independent predictors of improvement in both WR and delayed H/M. CONCLUSIONS: The CSN function was impaired in patients with AS, as assessed using MIBG scintigraphy. WR and delayed H/M improved immediately after TAVR. Improvement in CSN function may be related to echocardiographic AS severity at baseline before TAVR.

Comparative Analysis of the Paclitaxel-Eluting Peripheral Igaki-Tamai Stent and the Drug-Free Igaki-Tamai Stent Using Optical Coherence Tomography and Histological Analysis in a Porcine Iliac Artery Model.

BACKGROUND: The combination of a bioresorbable scaffold and antiproliferative drugs is a promising treatment for peripheral artery disease. The novel paclitaxel-eluting peripheral Igaki-Tamai stent (PTX-ITS) has the same backbone design as the drug-free peripheral Igaki-Tamai stent and a paclitaxel coating. Arterial responses to the PTX-ITS and ITS using optical coherence tomography (OCT) and histological analysis in a porcine iliac artery model were compared.Methods and Results:In total, 6 PTX-ITSs and 6 ITSs implanted in porcine iliac arteries were evaluated. Quantitative measurements of the scaffold, lumen, neointimal areas, and percent area stenosis were performed using OCT at 1 and 3 months. Histological evaluations (PTX-ITS [n=5], ITS [n=4]) were performed following euthanasia at 3 months. Injury, inflammation, endothelialization, and fibrin scores were measured. Baseline angiographic characteristics were similar in both groups. The ITS group showed significantly smaller scaffold areas than the PTX-ITS group at 1 month (18.50±3.62 mm2vs. 23.54±3.64 mm2; P=0.037) and 3 months (15.82±2.57 mm2vs. 21.67±3.57 mm2; P=0.009). Percent area stenosis was significantly lower in the PTX-ITS group at 3 months (28.70±7.24% vs. 40.36±7.07%; P=0.018). Histological evaluations revealed similar low-grade inflammatory reactions for both scaffolds. CONCLUSIONS: PTX-ITSs showed significantly better suppression of late scaffold shrinkage and lower in-scaffold stenosis for up to 3 months. Additionally, PTX-ITSs exhibited high biocompatibility, which is comparable to ITSs.

Importance of Preoperative Computed Tomography Assessment of the Membranous Septal Anatomy in Patients Undergoing Transcatheter Aortic Valve Replacement With a Balloon-Expandable Valve.

BACKGROUND: Cardiac conduction disturbance (CD) is the most frequent complication following transcatheter aortic valve replacement (TAVR). This study examined whether the anatomy of the membranous septum (MS) could provide useful information about the risk of CD following TAVR with a balloon-expandable valve (BEV).Methods and Results:Among 132 consecutive patients, 106 (mean age, 85.6±5.1 years; 75 females) were included in the study. Using preoperative CT and angiography, MS length and implantation depth (ID) were assessed. The MS length minus the prosthesis ID was calculated (∆MSID). Correlation between CD, defined as new-onset left-bundle branch block (LBBB) or the need for permanent pacemaker (PPM) within 1 week after the procedure, and MS length were evaluated. A total of 19 patients (18%) developed CD following TAVR. MS length was significantly shorter in these patients than in those without CD (5.3±1.3 vs. 6.6±1.4; P<0.001), and was the important predictor of CD (odds ratio [OR]: 0.43, 95% confidence interval [CI]: 0.27-0.69, P<0.001). When considering the pre- and postprocedural parameters, the ∆MSID was smaller in patients with CD (-1.7±1.5 vs. 0.8±1.9, P<0.001), and emerged as the important predictor of CD (OR: 0.47, 95% CI: 0.33-0.69, P<0.001). CONCLUSIONS: Short MS is associated with an increased risk of CD after TAVR with BEV.

Endovascular treatment of transplant renal artery stenosis based on hemodynamic assessment using a pressure wire: a case report.

BACKGROUND: Transplant renal artery stenosis (TRAS) is a serious complication after renal transplantation, leading to hypertension, deterioration in renal function, and/or graft loss. The incidence of TRAS reportedly varies from 1 to 23%, depending on its definition or diagnostic tools. The hemodynamic definition or therapeutic indication of TRAS is unclear. CASE PRESENTATION: A 66-year-old man with a history of diabetes, chronic kidney disease, and angina presented with a 2-week history of dyspnea and leg edema. He had undergone living-donor kidney transplantation for end-stage renal disease secondary to diabetic nephropathy 7 years earlier. He developed acute deterioration in renal function after the administration of an angiotensin II receptor blocker and required emergency hospitalization owing to acute congestive heart failure with pulmonary edema. A vasodilator and loop diuretics were administered following his admission, and the patient's symptoms resolved quickly. Further investigation, including magnetic resonance angiography and ultrasonography, revealed severe stenosis of the transplant renal artery. Renal arteriography and pressure gradient measurement using a 0.014-inch pressure wire were performed. The systolic pressure gradient was 40 mmHg, and the resting Pd/Pa ratio (ratio of mean distal to lesion and mean proximal pressures) was 0.90 without hyperemia. Hemodynamically significant stenosis was suspected. Intravascular ultrasonography revealed vessel shrinkage in the stenotic area, suggestive of the end-to-end anastomosis site. Pre-dilation using a 4-mm balloon, implantation of a 6-mm self-expandable stent, and post-dilatation using a 5-mm balloon were performed. Although the moderate stenosis persisted angiographically, the systolic pressure gradient dropped to 20 mmHg with the mean systolic pressure ratio increased to 0.95, which was considered an acceptable result. One month after the procedure, the patient's renal function and blood pressure control had significantly improved. CONCLUSIONS: Hemodynamic assessment using a pressure wire is useful in determining the appropriate therapeutic indication and endpoint of endovascular treatment of TRAS.

Fatal heart failure caused by severe pulmonary regurgitation, tricuspid regurgitation and late-onset mitral stenosis in an adult patient with Noonan syndrome: a case report.

BACKGROUND: In patients with Noonan syndrome (NS), cardiac disorders such as pulmonary valve stenosis (PS) or hypertrophic cardiomyopathy (HCM) are common. While some patients can develop heart failure associated with HCM, the long-term outcome of adult patients with NS is reported to be good. Fatal outcomes of heart failure in patients with NS but without HCM are rare. CASE PRESENTATION: We report a 25-year-old Japanese woman diagnosed with NS in adulthood. She exhibited short stature and minor facial dysmorphism and was diagnosed with PS at 1 year of age. After surgical valvuloplasty for PS at 6 years of age, her general condition became stable without specific medical treatment. She discontinued regular medical follow-up for PS. At 21 years of age, she developed acute decompensated heart failure, which was mainly right-sided heart failure due to severe pulmonary regurgitation (PR) and tricuspid regurgitation (TR). There was no evidence of HCM or PS recurrence. On the basis of the history of PS and characteristic physical features including short stature, webbed neck, and hypertelorism, she was clinically diagnosed with NS. At 25 years of age, she developed heart failure of both sides due to PR, TR and late-onset severe mitral stenosis (MS). The etiology of MS was uncertain. Owing to the patient's condition, surgical options were considered to be extremely high risk. She was treated with optimal medical treatment as well as the occasional abdominal cavity drainage for recurrent ascites; however, she died of decompensated heart failure at 27 years of age. CONCLUSIONS: We describe an adult patient with NS without HCM who died of heart failure caused by severe PR, TR and MS. Clinicians should recognize that ongoing or late-onset cardiac disorders can develop in patients with NS, and lead to fatal heart failure. Optimal medical follow-up to monitor cardiac function and early identification of heart failure are important.

"Pseudo aortoiliac bifurcation" leading to significant plaque shifting in the endovascular treatment of an aortoiliac bifurcation lesion: a case report.

BACKGROUND: Plaque shifting is a serious complication of endovascular treatment (EVT) for aortoiliac bifurcation lesions. It is challenging to predict the occurrence of unfavorable plaque shifting correctly. CASE PRESENTATION: We report the case of an 88-year-old Japanese woman who experienced constant pain at rest in her left leg. The ankle-brachial pressure index of her left leg was 0.57. Computed tomography (CT) angiography revealed severe stenosis of the left common iliac artery (CIA) and total occlusion of the left external iliac artery (EIA). We diagnosed the patient with acute exacerbation of a chronic limb ischemia and administered endovascular treatment (EVT) to treat the left CIA and EIA. The results of initial angiography agreed with those of CT angiography. After placing a self-expandable stent for the left CIA lesion, significant unfavorable plaque shifting occurred. From a comparison between pre- and post-stenting angiography, we realized that the plaque protrusion into the terminal aorta had formed a "pseudo aortoiliac bifurcation" that was situated more proximally compared to the true bifurcation. We had incorrectly assessed the height of the aortoiliac bifurcation and exact plaque position and had underestimated the risk of plaque shifting because of this misunderstanding. The patient ultimately developed fatal cholesterol embolization after EVT. CONCLUSIONS: Plaque protrusion into the terminal aorta can form a "pseudo aortoiliac bifurcation", causing the wrong estimation of the height of the aortoiliac bifurcation; "angiographically", the highest point is not always the true bifurcation. Careful assessment of initial angiography to detect the true aortoiliac bifurcation and exact plaque position is essential to avoid unfavorable plaque shifting.

Prostatic abscess in a patient with ST-elevation myocardial infarction: a case report.

BACKGROUND: In patients with ST-elevation myocardial infarction (STEMI), urinary tract infection is the most common infection-related complication. Prostatic abscess in a patient with STEMI is very rare. CASE PRESENTATION: We report the case of a 49-year-old Japanese man who developed fever and shaking chills during hospitalization for STEMI. We initially diagnosed catheter-associated urinary tract infection. However, subsequent contrast-enhanced computed tomography revealed multiple large abscesses in his prostate. We decided to treat with antimicrobial agents alone because the patient was receiving dual-antiplatelet therapy and discontinuation is very high risk for in-stent thrombosis. The patient recovered remarkably after treatment without drainage or surgery. CONCLUSIONS: Here, we described the world's first reported case of prostatic abscess in an immunocompetent patient with STEMI. Early removal of indwelling bladder catheters in patients with STEMI receiving dual-antiplatelet therapy is important to avoid development of prostatic abscess. Furthermore, unnecessary invasive instrumentation should be avoided or limited to diminish the risk of infections.

Cardiac CT: Competition, complimentary or confounder.

Coronary CT angiography (CCTA) has been gradually adopted into clinical practice over the last two decades. CCTA has high diagnostic accuracy, prognostic value, and unique features such as assessment of plaque composition. CCTA-derived functional assessment techniques such as fractional flow reserve and CT perfusion are also available and can increase the diagnostic specificity of the modality. These properties propound CCTA as a competitor of functional testing in diagnosis of obstructive CAD, however, utilizing CCTA in a concomitant fashion to potentiate the performance of the latter can lead to better patient care and may provide more accurate prognostic information. Although multiple diagnostic challenges such as evaluation of calcified segments, stents, and small distal vessels still exist, the technologic developments in hardware as well as growing incorporation of artificial intelligence to daily practice are all set to augment the diagnostic and prognostic role of CCTA in cardiovascular disorders.

The efficacy of inspiratory muscle training in patients with coronary artery disease: Protocol for a systematic review and meta-analysis.

BACKGROUND: Inspiratory muscle training (IMT) has been recognized as an effective form of training in patients with cardiovascular disease and heart failure. However, little is known about the efficacy of IMT in the treatment of patients with coronary artery disease (CAD). The aim of this systematic review will be to evaluate randomized controlled studies to understand the effect of IMT on CAD patients. METHOD: We will include randomized controlled trials evaluating the efficacy of IMT in patients 18 years and older diagnosed with CAD. Crossover trials, cluster-randomized, quasi-randomized, and non-randomized trials will be excluded. Study search will be conducted in major databases (MEDLINE, the Cochrane Central Register of Controlled Trials, Embase, and PEDro). The study intervention will be IMT independent of the duration, frequency, or intensity of training. The primary outcome will be quality of life, patient-reported health status, and all adverse events related to IMT. Secondary outcomes will include exercise capacity and respiratory muscle strength. The risk of bias will be evaluated based on the Cochrane Risk of Bias tool. Screening, data extraction, and quality assessment will be performed by two independent reviewers. If two or more studies are considered to be clinically homogeneous, a meta-analysis based on the random-effects model will be performed. The quality of evidence will be evaluated based on the GRADE approach. CONCLUSION: This systematic review will improve our understanding of the effects of IMT on CAD patients and potentially establish IMT as an alternative form of exercise training for the treatment of CAD. TRIAL REGISTRATION: Study registration. OSF registries (https://osf.io/3ch7m). Date registered: May 10, 2022. Registration DOI: https://doi.org/10.17605/OSF.IO/GVMY7.

Advances in Single-Photon Emission Computed Tomography: Hardware, Software, and Myocardial Flow Reserve.

The clinical presentation of coronary artery disease (CAD) has changed during the last 20 years with less ischemia on stress testing and more nonobstructive CAD on coronary angiography. Single-photon emission computed tomography (SPECT) myocardial perfusion imaging should include the measurement of myocardial flow reserve and assessment of coronary calcium for the diagnosis of nonobstructive CAD and coronary microvascular disease. SPECT/CT systems provide reliable attenuation correction for better specificity and low-dose CT for coronary calcium evaluation. SPECT MFR measurement is accurate, well validated, and repeatable.

The estimation of left ventricular function using prospective ECG-triggered coronary CT angiography.

BACKGROUND: Coronary computed tomography angiography (CCTA) is vital for diagnosing coronary artery disease; however, prospective ECG-triggered acquisition, minimizing radiation exposure, limits left ventricular (LV) ejection fraction (EF) evaluation. We aimed to assess the feasibility and utility of LVEF100msec, a new index for estimating LV function using volumetric changes during 100 msec within systole. METHODS: This retrospective study analyzed patients who underwent prospective ECG-triggered CCTA with systolic acquisition between January 2015 and June 2022. The LVEF100msec was calculated using the maximum and minimum LV volumes among the three phases (300, 350, and 400 msec post-QRS) and expressed as a percentage. Patients were classified into normal, mild-moderately reduced, or severely reduced LV function categories based on the reference test. The LVEF100msec was compared among groups, and the optimal cutoff value of LVEF100msec for predicting severe LV dysfunction was investigated. RESULTS: The study included 271 patients (median age â€‹= â€‹58 years, 52% male). LVEF was normal in 188 (69.4%), mild-moderately reduced in 57 (21.0%), and severely reduced in 26 (9.6%) patients. Median LVEF100msec value was 9.0 (6.7-12.6) for normal LV function, 4.7 (3.1-8.8) for mild-moderately reduced, and 2.9 (1.5-3.8) for severely reduced LV function. LVEF100msec values significantly differed among categories (p â€‹< â€‹0.001). The optimal LVEF100msec cutoff for severe LV dysfunction was 4.3%, with an AUC of 0.924, sensitivity of 88%, and specificity of 89%. CONCLUSION: The LVEF100msec may serve as a valuable indicator of severe LV dysfunction.

Left ventricular hypertrophy as a predictor of cardiovascular outcomes after transcatheter aortic valve replacement.

AIMS: This study aimed to clarify the relationship between cardiovascular prognosis and left ventricular hypertrophy (LVH) in patients with severe aortic stenosis who underwent transcatheter aortic valve replacement (TAVR) and to investigate the relationship between cardiac sympathetic nerve (CSN) function and these factors using 123 I-metaiodobenzylguanidine scintigraphy. METHODS AND RESULTS: In this single-centre, retrospective observational study, 349 patients who underwent TAVR at our institution between July 2017 and May 2020 were divided into two groups: those with severe LVH pre-operatively [severe LVH (+) group] and those without LVH pre-operatively [severe LVH (-) group]. The rates of freedom from cardiovascular events (cardiovascular death and heart failure hospitalization) were compared. The relationship between changes in left ventricular mass index (LVMi) and changes in delay heart-mediastinum ratio (H/M) from before TAVR to 6 months after TAVR was also investigated. The event-free rate was significantly lower in the severe LVH (+) group (87.1% vs. 96.0%, log-rank P = 0.021). The severe LVH (+) group exhibited a significantly lower delay H/M value, scored by 123 I-metaiodobenzylguanidine scintigraphy, than the severe LVH (-) group (2.33 [1.92-2.67] vs. 2.67 [2.17-3.68], respectively, P < 0.001). Moreover, the event-free rate of post-operative cardiovascular events was lower among patients with a delay H/M value < 2.50 than that among other patients (87.7% vs. 97.2%, log-rank P = 0.012). LVMi was significantly higher (115 [99-130] vs. 90 [78-111] g/m2 , P < 0.001) and delay H/M value was significantly lower (2.53 [1.98-2.83] vs. 2.71 [2.25-3.19], P = 0.025) in the severe LVH (+) group than in the severe LVH (-) group at 6 months after TAVR. Patients with improved LVH at 6 months after TAVR also had increased delay H/M (from 2.51 [2.01-2.81] to 2.67 [2.26-3.02], P < 0.001), whereas those without improved LVH had no significant change in delay H/M (from 2.64 [2.23-3.06] to 2.53 [1.97-3.00], P = 0.829). CONCLUSIONS: Severe LVH before TAVR is a prognostic factor for poor post-operative cardiovascular outcomes. LVH associated with aortic stenosis and CSN function are correlated, suggesting their involvement in LVH prognosis.