Outcomes of Transcatheter Aortic Valve Replacement in the United Arab Emirates: Real-world, Single-centre Experience from an Emerging Programme.

Background: Data on outcomes of transcatheter aortic valve replacement (TAVR) in the Middle East, particularly in the United Arab Emirates (UAE), are limited. Whether centres with a low volume of patients requiring the procedure can achieve similar outcomes as those reported in pivotal clinical trials remains unclear. This study evaluates procedural outcomes of patients undergoing TAVR in a newly established programme in the UAE. Methods: Procedural outcomes of consecutive patients who underwent transfemoral TAVR at a single centre in the UAE between January 2016 and November 2021 were compared with those at centres in the lowest quartile (Q1) of procedural volume in the Transcatheter Valve Therapy Registry, which covers centres in the US. Results: Among the 183 patients included in the study, the median age was 76 years (interquartile range [IQR] 71-82), and 42.1% of patients were women, with a median Society of Thoracic Surgeons predicted risk of mortality score of 4.6 (IQR 2.9-7.5). Most of the patients (93.3%) received a balloon-expandable valve. All-cause death within 30 days, stroke and major vascular complications occurred in 0.6%, 0.6% and 2.2% of patients, respectively, compared with 3.1%, 2.2% and 4% in patients treated at Q1 hospitals. Conclusion: Patients undergoing transfemoral TAVR at an emerging centre in the Middle East had favourable outcomes compared with those performed at Q1 hospitals in the US. These findings suggest that careful patient selection for TAVR is critical and may help optimise patient outcomes, especially when procedural volumes are low.

Management of acute aortic services during the COVID-19 pandemic: a retrospective cohort study from the Middle East.

COVID-19 created a challenging situation for cardiac surgery and associated acute care programs around the world. While non-urgent cases might be postponed, operating on life-threatening conditions, including type A aortic dissection (TAAD), must be sustained despite the ongoing pandemic. Therefore, the authors investigated the impact of the COVID-19 pandemic on their urgent aortic program. Methods: The authors included consecutive patients presenting with TAAD (n=36) in the years 2019 and 2020 [pre-pandemic period (2019; n=16) and the pandemic era (2020; n=20)] at a tertiary care centre. Patient characteristics, TAAD presenting symptoms, operative techniques, postoperative outcomes, and length of stay were determined retrospectively using chart review and were compared between both years. Results: An increase occurred in the absolute number of TAAD referrals during the pandemic era. Patients were featured by younger age of presentation (pre-pandemic group: 47.6±18.7, and the pandemic group: 50.6±16.2 years, P=0.6) in contrast to Western data but showed similar male predominance (4:1) in both groups. There was no statistical difference in baseline comorbidities between the groups. Length of hospital stay [20 (10.8-56) vs. 14.5 (8.5-53.3) days, P=0.5] and intensive care unit stay [5 (2.3-14.5) vs. 5 (3.3-9.3) days, P=0.4] were comparable between both groups. Low rates of postoperative complications were registered in both groups with no significant between-group difference. There was no significant difference in the rates of in-hospital mortality between both groups [12.5% (2) vs. 10% (2), P=0.93]. Conclusions: Compared with the pre-pandemic era (2019), there was no difference in resource utilisation and clinical outcomes of patients presenting with TAAD during the first year of COVID-19 pandemic (2020). Structural departmental re-configuration and optimal personal protective equipment utilisation warrant maintained satisfactory outcomes in critical healthcare scenarios. Future studies are required to further investigate aortic care delivery during such challenging pandemics.

Management of Patients With Tricuspid Valve Endocarditis and Ongoing Intravenous Drug Abuse: Less Is More.

Right-sided infective endocarditis in patients with intravenous drug abuse portends a worse prognosis. Data on optimal management strategy in this situation are scarce. We describe outcomes of 2 different treatment strategies, including a patient treated conservatively with favorable intermediate-term results and another who was treated surgically and developed recurrent endocarditis. (Level of Difficulty: Intermediate.).

Early Identification and Management of Heart Failure in Patients with Diabetes Mellitus in the United Arab Emirates: A Call to Action.

Heart failure (HF) is a common and serious complication of diabetes mellitus (DM) that remains widely under-recognized. Multidisciplinary management protocols for patients with concurrent DM and HF are not widely utilized in the Middle East/Gulf region, particularly in the United Arab Emirates. Since early identification of patients with DM and HF will likely lead to initiation of therapies known to prevent adverse cardiovascular events and subsequently improve patient prognosis, we aim to highlight the importance of early recognition of HF in diabetic patients. We will also describe existing management challenges in the region, especially the lack of multidisciplinary care and emphasize the role of newer anti-diabetic therapies in preventing and treating HF. Most importantly, this call-to-action proposes a collaborative approach to the care of diabetic patients with HF involving primary care physicians, endocrinologists, and cardiologists.

From Clinical Clues to Final Diagnosis: The Return of Detective Work to Clinical Medicine in Cardiac Amyloidosis.

Cardiac amyloidosis is frequently misdiagnosed, denying patients the opportunity for timely and appropriate management of the disease. The purpose of this review and case studies is to raise awareness of the diagnostic "red flags" associated with cardiac amyloidosis and the currently available non-invasive strategies for diagnosis. The review focuses on the identification of one of the two main types of cardiac amyloidosis, transthyretin amyloid cardiomyopathy, and non-invasive tools to distinguish this from light-chain amyloidosis. A diagnostic algorithm centered around the use of non-invasive imaging and laboratory analysis is presented. The algorithm generates four differential diagnoses for patients presenting with signs and symptoms consistent with cardiac amyloidosis. Case examples are presented, representing the four potential outcomes of diagnosis using the algorithm. The review provides a guide on how to recognize the often-overlooked presentations of this disease in clinical practice. Non-invasive imaging techniques and diagnostic tools that do not require the involvement of a specialty center have allowed for the improved diagnosis of cardiac amyloidosis. Timely diagnosis of this life-threatening disease is essential for optimal management and it is imperative that clinicians have a high index of suspicion for patients presenting with "red flag" symptoms.

Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention in Patients With Renal Dysfunction.

Although contemporary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is performed with high success rates, 10% to 13% of patients presenting with CTOs have chronic kidney disease (CKD), and the comparative safety, efficacy, and health status benefit of CTO PCI in these patients, has not been well defined. We examined the association of baseline renal function with periprocedural major adverse cardiovascular and cerebral events and health status outcomes in 957 consecutive patients (mean age 65.3 ± 10.3 years, 19.4% women, 90.3% white, 23.6 CKD [estimated glomerular filtration rate {eGFR} < 60]) in the OPEN-CTO (Outcomes, Patients Health Status, and Efficiency in Chronic Total Occlusions Registry) study. Hierarchical multivariable regression models were used to examine the independent association of baseline eGFR with technical success, periprocedural complications and change in health status, using Seattle Angina Questionnaire (SAQ) over 1 year. Crude rates of acute kidney injury were higher (13.5% vs 4.4%, p <0.001) and technical success lower (81.8% vs 88.4%, p = 0.01) in patients with CKD. There were no significant differences in other periprocedural complications. After adjustment for confounding factors, there was no significant association of baseline eGFR with technical success or periprocedural major adverse cardiovascular and cerebral events (death, myocardial infarction, emergent bypass surgery, stroke, perforation), whereas patients with lower eGFR had higher rates of acute kidney injury. The difference in SAQ summary score, between patients on the 10th and 90th percentile for baseline eGFR distribution was not clinically significant (1 month: -0.91; 1 year: -3.06 points). In conclusion, CTO PCI success, complication rates, and the health status improvement after CTO PCI are similar in patients across a range of baseline eGFRs.

Temporal trends in test utilization and prevalence of ischaemia with positron emission tomography myocardial perfusion imaging.

AIMS: To examine whether test utilization and prevalence of ischemia with positron emission tomography (PET) myocardial perfusion imaging (MPI) follow the previously described trends with single photon computed tomography (SPECT). METHODS AND RESULTS: MPI studies performed between January 2003 and December 2017 were identified. Number of PET and SPECT MPI studies performed per year was determined. Trends in the proportion of studies showing any ischaemia (>0%) with both modalities were compared before and after adjusting for baseline differences in patient characteristics using propensity scores. Interaction between imaging modality and year of testing was examined using modified Poisson regression. A total of 156 244 MPI studies were performed (30% PET and 70% SPECT). Between 2003 and 2017, the number of PET studies increased from 18 to 61 studies/1000 patient encounters, while SPECT volumes declined from 169 to 34/1000 patient encounters (P < 0.001 for within-group comparisons). The prevalence of any ischaemia in SPECT-tested patients declined from 53.9% to 28.3% between 2003 and 2017, whereas ischaemia prevalence in PET-tested patients declined from 57.2% to 38.2% (P < 0.001 for within-modality comparisons), with more PET studies showing ischaemia compared to SPECT [relative risk (RR) 1.44, 95% confidence interval (CI) 1.42-1.47; P < 0.001]. After propensity score matching of 26 066 patients tested with SPECT with 26 066 patients tested with PET, the between-modality difference in ischaemia prevalence was significantly attenuated, with a slightly higher overall likelihood of detecting ischaemia with PET compared to SPECT (RR 1.08, 95% CI 1.05-1.11; P < 0.001). CONCLUSIONS: Utilization of PET MPI at a large-volume referral centre increased significantly between 2003 and 2017. Despite a significant decrease in the prevalence of ischaemia with SPECT and PET during the same period, the decline was less with PET, perhaps related to baseline risk of tested patients.

Drivers of radiation dose reduction with myocardial perfusion imaging: A large health system experience.

BACKGROUND: Despite increasing emphasis on reducing radiation exposure from myocardial perfusion imaging (MPI), the use of radiation-sparing practices (RSP) at nuclear laboratories remains limited. Defining real-world impact of RSPs on effective radiation dose (E) can potentially further motivate their adoption. METHODS: MPI studies performed between 1/2010 and 12/2016 within a single health system were included. Mean E was compared between sites with 'basic' RSP (defined as elimination of thallium-based protocols and use of stress-only (SO) imaging on conventional single photon emission computed tomography (SPECT) cameras) and those with 'advanced' capabilities (sites that additionally used solid-state detector (SSD) SPECT cameras, advanced post-processing software (APPS) or positron emission tomography (PET) imaging), after matching patients by age, gender, and weight. Contributions of individual RSP to E reduction were determined using multiple linear regression after adjusting for factors affecting tracer dose. RESULTS: Among 55,930 MPI studies performed, the use of advanced RSP was associated with significantly lower mean E compared to basic RSP (7 ± 5.6 mSv and 16 ± 5.4 mSv, respectively; P < 0.001), with a greater likelihood of achieving E < 9 mSv (65.7% vs. 10.8%, respectively; OR 15.8 [95% CI 14 to 17.8]; P < 0.0001). Main driver of E reduction was SO-SSD SPECT (mean reduction = 11.5 mSv), followed by use of SO-SPECT + APPS (mean reduction = 10.1 mSv), ;ET (mean reduction = 9.7 mSv); and elimination of thallium protocols (mean reduction = 9.1 mSv); P < 0.0001 for all comparisons. CONCLUSION: In a natural experiment with implementation of radiation-saving practices at a large health system, stress-only protocols used in conjunction with modern SPECT technologies, the use of PET and elimination of thallium-based protocols were associated with greatest reductions in radiation dose. Availability of several approaches to dose reduction within a health system can facilitate achievement of targeted radiation benchmarks in a greater number of performed studies.

Myocardial blood flow reserve assessed by positron emission tomography myocardial perfusion imaging identifies patients with a survival benefit from early revascularization.

AIMS: Positron emission tomography (PET) myocardial perfusion imaging (MPI) can non-invasively measure myocardial blood flow reserve (MBFR). We aimed to examine whether MBFR identifies patients with a survival benefit after revascularization, helping to guide post-test management. METHODS AND RESULTS: We examined all-cause mortality in 12 594 consecutive patients undergoing Rb82 rest/stress PET MPI from January 2010 to December 2016, after excluding those with cardiomyopathy, prior coronary artery bypass surgery (CABG), and missing MBFR. Myocardial blood flow reserve was calculated as the ratio of stress to rest absolute myocardial blood flow. A Cox model adjusted for patient and test characteristics, early revascularization (percutaneous coronary intervention or CABG ≤90 days of MPI), and the interaction between MBFR and early revascularization was developed to identify predictors of all-cause mortality. After a median follow-up of 3.2 years, 897 patients (7.1%) underwent early revascularization and 1699 patients (13.5%) died. Ischaemia was present in 4051 (32.3%) patients, with 1413 (11.2%) having ≥10% ischaemia. Mean MBFR was 2.0 ± 1.3, with MBFR <1.8 in 4836 (38.5%). After multivariable adjustment, every 0.1 unit decrease in MBFR was associated with 9% greater hazard of all-cause death (hazard ratio 1.09, 95% confidence interval 1.08-1.10; P < 0.001). There was a significant interaction between MBFR and early revascularization (P < 0.001); such that patients with MBFR ≤1.8 had a survival benefit with early revascularization, regardless of type of revascularization or level of ischaemia. CONCLUSION: Myocardial blood flow reserve on PET MPI is associated with all-cause mortality and can identify patients who receive a survival benefit with early revascularization compared to medical therapy. This may be used to guide revascularization, and prospective validation is needed.

The Evolving Landscape of Impella Use in the United States Among Patients Undergoing Percutaneous Coronary Intervention With Mechanical Circulatory Support.

BACKGROUND: Impella was approved for mechanical circulatory support (MCS) in 2008, but large-scale, real-world data on its use are lacking. Our objective was to describe trends and variations in Impella use, clinical outcomes, and costs across US hospitals in patients undergoing percutaneous coronary intervention (PCI) treated with MCS (Impella or intra-aortic balloon pump). METHODS: From the Premier Healthcare Database, we analyzed 48 306 patients undergoing PCI with MCS at 432 hospitals between January 2004 and December 2016. Association analyses were performed at 3 levels: time period, hospital, and patient. Hierarchical models with propensity adjustment were used for association analyses. We examined trends and variations in the proportion of Impella use, and associated clinical outcomes (in-hospital mortality, bleeding requiring transfusion, acute kidney injury, stroke, length of stay, and hospital costs). RESULTS: Among patients undergoing PCI treated with MCS, 4782 (9.9%) received Impella; its use increased over time, reaching 31.9% of MCS in 2016. There was wide variation in Impella use across hospitals (>5-fold variation). Specifically, among patients receiving Impella, there was a wide variation in outcomes of bleeding (>2.5-fold variation), and death, acute kidney injury, and stroke (all ≈1.5-fold variation). Adverse outcomes and costs were higher in the Impella era (years 2008-2016) versus the pre-Impella era (years 2004-2007). Hospitals with higher Impella use had higher rates of adverse outcomes and costs. After adjustment for the propensity score, and accounting for clustering of patients by hospitals, Impella use was associated with death: odds ratio, 1.24 (95% CI, 1.13-1.36); bleeding: odds ratio, 1.10 (95% CI, 1.00-1.21); and stroke: odds ratio, 1.34 (95% CI, 1.18-1.53), although a similar, nonsignificant result was observed for acute kidney injury: odds ratio, 1.08 (95% CI, 1.00-1.17). CONCLUSIONS: Impella use is rapidly increasing among patients undergoing PCI treated with MCS, with marked variability in its use and associated outcomes. Although unmeasured confounding cannot be ruled out, when analyzed by time periods, or at the hospital level or the patient level, Impella use was associated with higher rates of adverse events and costs. More data are needed to define the appropriate role of MCS in patients undergoing PCI.

Comparison of the Effect of Catheter Ablation for Atrial Fibrillation on All-Cause Hospitalization in Patients With Versus Without Heart Failure (from the Nationwide Readmission Database).

Catheter ablation (CA) is associated with reduced arrhythmia recurrence and improved quality of life in patients with atrial fibrillation (AF). Heart failure (HF) is common in patients with AF and is associated with a high hospitalization burden. The real-world association between CA and rates of subsequent hospitalization in patients with AF and HF has not been well studied. Patients who underwent CA for AF during the middle 4 months of each year 2010 to 2015 were identified using the Nationwide Readmission Database. Patients were grouped according to the HF status and HF patients were stratified to reduced versus preserved ejection fraction (EF) using ICD-9 codes. Rates of all-cause hospitalization 120 days before and after index admission were compared using the McNemar's test, before and after matching for baseline characteristics. A total of 10,966 patients met inclusion criteria, including 1,950 with HF. In the HF group, all-cause hospitalization rates changed from 45.8% before CA to 33.2% after (p <0.001). Corresponding rates for non-HF patients were 23.8% and 19.7% (p< 0.001) with a greater relative reduction in hospitalizations seen in the HF group (27.5% vs 17.2%; p value <0.001). The difference in relative reduction persisted after adjustment by propensity score matching. The relative reduction in hospitalization rates was similar in HF patients with reduced and preserved EF with 25.2% and 28.5%, respectively. In conclusion, CA for AF was followed by a significant reduction in all-cause hospitalization rates. Patients with HF, regardless of EF, showed a greater reduction in admissions.

Association Between Diastolic Dysfunction and Health Status Outcomes in Patients Undergoing Transcatheter Aortic Valve Replacement.

OBJECTIVES: The aim of this study was to assess the association of baseline left ventricular diastolic dysfunction (LVDD) with health status outcomes of patients undergoing transcatheter aortic valve replacement (TAVR). BACKGROUND: Although LVDD in patients with aortic stenosis is associated with higher mortality after TAVR, it is unknown if it is also associated with health status recovery. METHODS: In a cohort of 304 patients with interpretable echocardiograms, undergoing TAVR, LVDD was categorized at baseline as absent (grade 0), mild (grade 1), moderate (grade 2), or severe (grade 3). Disease-specific health status was assessed using the 12-item Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ-OS) at baseline and at 1-month and 12-month follow-up. Association of baseline LVDD with health status at baseline and follow-up after TAVR was assessed using a linear trend test, and association with health status recovery (change in KCCQ-OS) was examined using a linear mixed model adjusting for baseline KCCQ-OS. RESULTS: Twenty-four (7.9%), 54 (17.8%), 186 (61.2%), and 40 (13.2%) patients had LVDD grades of 0, 1, 2, and 3, respectively. Baseline KCCQ-OS was 61.3 ± 22.7, 51.0 ± 26.1, 44.7 ± 25.7, and 44.4 ± 21.9 (p = 0.004) in patients with LVDD grades of 0, 1,2 and 3. At 1 and 12 months after TAVR, LVDD was not associated with KCCQ-OS. Recovery in KCCQ-OS after TAVR was substantial and similar in patients across all severities of LVDD. CONCLUSIONS: Although LVDD is associated with health status prior to TAVR, patients across all severities of LVDD have similar recovery in health status after TAVR.

Extent of Myocardial Ischemia on Positron Emission Tomography and Survival Benefit With Early Revascularization.

BACKGROUND: Prior studies with single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) have shown a survival benefit with early revascularization in patients with >10% to 12.5% ischemic myocardium. The relationship among positron emission tomography (PET)-derived extent of ischemia, early revascularization, and survival is unknown. OBJECTIVES: The purpose of this study was to evaluate the association among percent ischemia on PET MPI, revascularization, and survival. METHODS: A total of 16,029 unique consecutive patients who were undergoing Rubidium-82 rest-stress PET MPI from 2010 to 2016 were included. Patients with known cardiomyopathy and nondiagnostic perfusion results were excluded. Percent ischemic myocardium was estimated from a 17-segment model. Propensity scoring was used to account for nonrandomized referral to early revascularization (90 days of PET). A Cox model was developed, adjusting for propensity scores for early revascularization and percent ischemia, and an interaction between ischemia and early revascularization was tested. RESULTS: Median follow-up was 3.7 years. Overall, 1,277 (8%) patients underwent early revascularization and 2,493 (15.6%) died (738 cardiac). Nearly 37% of patients (n = 5,902) had ischemia, with 13.5% (n = 2,160) having ≥10%. In propensity-adjusted analyses, there was a significant interaction between ischemia and early revascularization (p < 0.001 for all-cause and cardiac death), such that patients with greater ischemia had improved survival with early revascularization, with a potential ischemia threshold at 5% (upper limit 95% confidence interval at 10%). There was no differential association between ischemia and early revascularization on death based on history of known coronary artery disease (interaction p = 0.72). CONCLUSIONS: In a contemporary cohort of patients undergoing PET MPI, patients with greater ischemia had a survival benefit from early revascularization. On exploratory analyses, this threshold was lower than that previously reported for SPECT. These findings require future validation in prospective cohorts or trials.

Randomized Comparison of Clinical Effectiveness of Pharmacologic SPECT and PET MPI in Symptomatic CAD Patients.

OBJECTIVES: This study compared the clinical effectiveness of pharmacologic stress myocardial perfusion imaging (MPI) plus positron emission tomography (PET) with single-photon emission computed tomography (SPECT) in patients with known coronary artery disease (CAD) presenting with symptoms suggestive of ischemia. BACKGROUND: Although PET MPI has been shown to have higher diagnostic accuracy in detecting hemodynamically significant CAD than SPECT MPI, whether this impacts downstream management has not been formally evaluated in randomized trials. METHODS: This study consisted of a single-center trial in which patients with known CAD and suspected ischemia were randomized to undergo PET or attenuation-corrected SPECT MPI between June 2009 and September 2013. Post-test management was at the discretion of the referring physician, and patients were followed for 12 months. The primary endpoint was diagnostic failure, defined as unnecessary angiography (absence of ≥50% stenosis in ≥1 vessel) or additional noninvasive testing within 60 days of the MPI. Secondary endpoints were post-test escalation of antianginal therapy, referral for angiography, coronary revascularization, and health status at 3, 6, and 12 months. RESULTS: A total of 322 patients with an evaluable MPI were randomized (n = 161 in each group). At baseline, 88.8% of patients were receiving aspirin therapy, 76.7% were taking beta-blockers, and 77.3% were taking statin therapy. Diagnostic failure within 60 days occurred in only 7 patients (2.2%) (3 [1.9%] in the PET group and 4 [2.5%] in the SPECT group; p = 0.70). There were no significant differences between the 2 groups in subsequent rates of coronary angiography, coronary revascularization, or health status at 3, 6, and 12 months of follow-up (all p values ≥0.20); however, when subjects were stratified by findings on MPI in a post hoc analysis, those with high-risk MPI on PET testing had higher rates of angiography and revascularization on follow-up than those who had SPECT MPI, whereas those undergoing low-risk PET studies had lower rates of both procedures than those undergoing SPECT (interaction between randomized modality ∗high-risk MPI for 12-month catheterization [p = 0.001] and 12-month revascularization [p = 0.09]). CONCLUSIONS: In this contemporary cohort of symptomatic CAD patients who were optimally medically managed, there were no discernible differences in rates of diagnostic failure at 60 days, subsequent coronary angiography, revascularization, or patient health status at 1 year between patients evaluated by pharmacologic PET compared with those evaluated by SPECT MPI. Downstream invasive testing rates with PET MPI were more consistent with high-risk features than those with SPECT MPI. (Effectiveness Study of Single Photon Emission Computed Tomography [SPECT] Versus Positron Emission Tomography [PET] Myocardial Perfusion Imaging; NCT00976053).