The mechanistic pathways of oxidative stress in aortic stenosis and clinical implications.

Despite the elucidation of the pathways behind the development of aortic stenosis (AS), there remains no effective medical treatment to slow or reverse its progress. Instead, the gold standard of care in severe or symptomatic AS is replacement of the aortic valve. Oxidative stress is implicated, both directly as well as indirectly, in lipid infiltration, inflammation and fibro-calcification, all of which are key processes underlying the pathophysiology of degenerative AS. This culminates in the breakdown of the extracellular matrix, differentiation of the valvular interstitial cells into an osteogenic phenotype, and finally, calcium deposition as well as thickening of the aortic valve. Oxidative stress is thus a promising and potential therapeutic target for the treatment of AS. Several studies focusing on the mitigation of oxidative stress in the context of AS have shown some success in animal and in vitro models, however similar benefits have yet to be seen in clinical trials. Statin therapy, once thought to be the key to the treatment of AS, has yielded disappointing results, however newer lipid lowering therapies may hold some promise. Other potential therapies, such as manipulation of microRNAs, blockade of the renin-angiotensin-aldosterone system and the use of dipeptidylpeptidase-4 inhibitors will also be reviewed.

One-year outcomes of patients with ST-segment elevation myocardial infarction during the COVID-19 pandemic.

The pandemic has led to adverse short-term outcomes for patients with ST-segment elevation myocardial infarction (STEMI). It is unknown if this translates to poorer long-term outcomes. In Singapore, the escalation of the outbreak response on February 7, 2020 demanded adaptation of STEMI care to stringent infection control measures. A total of 321 patients presenting with STEMI and undergoing primary percutaneous coronary intervention at a tertiary hospital were enrolled and followed up over 1-year. They were allocated into three groups based on admission date-(1) Before outbreak response (BOR): December 1, 2019-February 6, 2020, (2) During outbreak response (DOR): February 7-March 31, 2020, and (3) control group: November 1-December 31, 2018. The incidence of cardiac-related mortality, cardiac-related readmissions, and recurrent coronary events were examined. Although in-hospital outcomes were worse in BOR and DOR groups compared to the control group, there were no differences in the 1-year cardiac-related mortality (BOR 8.7%, DOR 7.1%, control 4.8%, p = 0.563), cardiac-related readmissions (BOR 15.1%, DOR 11.6%, control 12.0%, p = 0.693), and recurrent coronary events (BOR 3.2%, DOR 1.8%, control 1.2%, p = 0.596). There were higher rates of additional PCI during the index admission in DOR, compared to BOR and control groups (p = 0.027). While patients admitted for STEMI during the pandemic may have poorer in-hospital outcomes, their long-term outcomes remain comparable to the pre-pandemic era.

Inter-Ethnic Differences in Valvular Dysfunction, Aortopathy, and Progression of Disease of an Asian Bicuspid Aortic Valve Population.

BACKGROUND: There are differences in bicuspid aortic valve (BAV) characteristics between Asian and European populations, but little is known about the inter-ethnic differences in bicuspid valve function and aortic root dimensions within the diverse Asian population. METHODS: From 1992-2017, 562 patients with index echocardiographic diagnosis of BAV in a tertiary health care institution in Singapore were analysed according to their ethnic groups: Chinese, Malay, Indian, and Eurasian. Study outcomes included BAV complications (infective endocarditis, aortic dissection) and clinical outcomes (aortic valve surgery, aortic root surgery, all-cause mortality). Total events were defined as composite outcome of all BAV complications and outcomes. Aortic dimensions and aortic dilatation rates were also studied. RESULTS: There were 379 (67.5%) Chinese, 79 (14.0%) Malay, 73 (13.0%) Indian, and 31 (5.5%) Eurasian patients. Type 1 BAV (58.5%) was the most prevalent BAV morphology, with moderate-to-severe aortic stenosis (AS) (36.8%) being the most common complication in the overall population. There was a higher prevalence of type 0 BAV in Chinese and Indian groups, and type 1 BAV with fusion of left-right coronary cusp in Eurasian and Malay groups (p=0.082). There was no difference in significant AS among groups. The highest prevalence of moderate-to-severe aortic regurgitation was observed amongst the Eurasian group, followed by Chinese, Indian, and Malay groups (p=0.033). The Chinese group had the largest mean indexed diameters of the aortic root. Multivariable linear regression demonstrated that only the Chinese had significantly larger indexed diameters in the aortic annulus, sinotubular junction (STJ), and ascending aorta (AA), relative to the Eurasian group, after adjusting for age, sex, smoking, hypertension, hyperlipidaemia, diabetes, and aortic regurgitation. On follow-up echocardiography, there was a trend towards the highest dilatation rates of sinus of Valsalva and STJ amongst Indian, and AA amongst Malay groups. Kaplan-Meier curves showed the highest incidence of total events amongst Chinese, followed by Malay, Indian and Eurasian (log-rank=9.691; p=0.021) patients. CONCLUSION: There were differences in BAV morphology, valve dysfunction, aortopathy, and prognosis within the Asian population. Chinese patients had one of the highest prevalence of significant aortic regurgitation, with the largest aortic dimensions and worst outcomes compared with other Asian ethnicities. Closer surveillance is warranted in BAV patients within the Asian population.

Post-ST-Segment Elevation Myocardial Infarction Follow-Up Care During the COVID-19 Pandemic and the Possible Benefit of Telemedicine: An Observational Study.

Background: Infectious control measures during the COVID-19 pandemic have led to the propensity toward telemedicine. This study examined the impact of telemedicine during the pandemic on the long-term outcomes of ST-segment elevation myocardial infarction (STEMI) patients. Methods: This study included 288 patients admitted 1 year before the pandemic (October 2018-December 2018) and during the pandemic (January 2020-March 2020) eras, and survived their index STEMI admission. The follow-up period was 1 year. One-year primary safety endpoint was all-cause mortality. Secondary safety endpoints were cardiac readmissions for unplanned revascularisation, non-fatal myocardial infarction, heart failure, arrythmia, unstable angina. Major adverse cardiovascular events (MACE) was defined as the composite outcome of each individual safety endpoint. Results: Despite unfavorable in-hospital outcomes among patients admitted during the pandemic compared to pre-pandemic era, both groups had similar 1-year all-cause mortality (11.2 vs. 8.5%, respectively, p = 0.454) but higher cardiac-related (14.1 vs. 5.1%, p < 0.001) and heart failure readmissions in the pandemic vs. pre-pandemic groups (7.1 vs. 1.7%, p = 0.037). Follow-up was more frequently conducted via teleconsultations (1.2 vs. 0.2 per patient/year, p = 0.001), with reduction in physical consultations (2.1 vs. 2.6 per patient/year, p = 0.043), during the pandemic vs. pre-pandemic era. Majority achieved guideline-directed medical therapy (GDMT) during pandemic vs. pre-pandemic era (75.9 vs. 61.6%, p = 0.010). Multivariable Cox regression demonstrated achieving medication target doses (HR 0.387, 95% CI 0.164-0.915, p = 0.031) and GDMT (HR 0.271, 95% CI 0.134-0.548, p < 0.001) were independent predictors of lower 1-year MACE after adjustment. Conclusion: The pandemic has led to the wider application of teleconsultation, with increased adherence to GDMT, enhanced medication target dosing. Achieving GDMT was associated with favorable long-term prognosis.

Prognostic Implications of Bicuspid and Tricuspid Aortic Valve Phenotype on Progression of Moderate Aortic Stenosis and Ascending Aorta Dilatation.

Studies on the impact of aortic valve anatomy (bicuspid aortic valve [BAV] or tricuspid aortic valve [TAV]) on the progression of moderate aortic stenosis (AS) and ascending aorta (AA) dilatation and its prognostic implications are limited. From 1991 to 2016, 288 asymptomatic patients with moderate AS detected during index echocardiography with at least 1 year of echocardiographic follow-up were retrospectively studied. Baseline clinical and echocardiographic characteristics were compared between patients with BAV (n = 80) and patients with TAV (n = 208). Co-primary outcomes were 1-year hemodynamic and anatomic progression of AS and AA dilatation. Secondary end points were the incidence of AA rapid progressors, all-cause mortality, aortic valve replacement, and congestive heart failure. Determinants of AS progression, AA diameters, AA dilatation, and prognostic outcomes were evaluated. Similar 1-year progression of the aortic valve peak velocity, Vmax (9 ± 18 vs 9 ± 23 cm/s), mean gradient (1.5 ± 2.3 vs 1.3 ± 3.2 mm Hg), and aortic valve area (AVA) (-0.04 ± 0.09 vs -0.05 ± 0.10 cm2) were noted for BAV and TAV groups, respectively. One-year progressions of AA were similar at Valsalva (0.11 ± 0.88 vs 0.14 ± 1.10 mm) and tubular levels (0.12 ± 0.68 vs 0.30 ± 1.51 mm) in BAV and TAV groups, respectively. A trend toward increased rapid AA progression in patients with BAV (31.3%) was observed compared with patients with TAV (14.8%, p = 0.099). BAV was associated with progression of Vmax (ß = 0.17, p = 0.036), the dimensionless index (ß = -0.17, p = 0.008), and AVA (ß = -0.14, p = 0.048), but not mean gradient after adjusting for age, baseline severity indexes, gender, hypertension, diabetes, and body surface area. Although BAV was a determinant of larger baseline AA diameter, there was no significant association between BAV and AA rapid progressors. Adjusted Kaplan-Meier curves demonstrated no differences in congestive heart failure, aortic valve replacement, or mortality between valve morphology. In conclusion, there was a similar 1-year disease progression in terms of AVA, Vmax, mean gradient, and AA diameters between patients with BAV and patients with TAV. BAV was associated with a significant increase in Vmax, dimensionless index, and AVA after adjusting for important confounders. Close and prolonged follow-up is warranted in both groups of patients.

Comparison of Outcomes of Asymptomatic Moderate Aortic Stenosis With Preserved Left Ventricular Ejection Fraction in Patients ≥80 Years Versus 70-79 Years Versus <70 Years.

Aortic stenosis (AS) is increasingly diagnosed in the aging population with more studies focused on the prognostic outcomes of severe asymptomatic AS. However, little is known about the outcomes of moderate asymptomatic AS in the elderly population. From 2001 to 2020, 738 consecutive patients with asymptomatic moderate AS with preserved left ventricular ejection fraction were studied. They were allocated according to the age group at the index echocardiography: very elderly (≥80 years), elderly (70 to 79 years) and control group (<70 years). The primary study outcomes were aortic valve replacement (AVR), congestive cardiac failure (CCF) and all-cause mortality. Overall, about one-third of the subjects were in the very elderly, elderly and control groups each. The median follow-up duration was 114.2 (interquartile range, 27.0 to 183.7) months. There was significantly higher all-cause mortality in the very elderly group (47.9%) followed by elderly (34.8%) and control group (21.9%). Similarly, there was significantly higher CCF rates in the very elderly group (5.8%) compared to elderly (5.1%) and control group (2.8%). There were significantly lower rates of AVR offered and completed in the very elderly group compared to control group. Multivariable logistic regression demonstrated that age ≥80 years remained an independent predictor of mortality after adjusting for important prognostic cofounders (Adjusted HR 2.424, 95% CI 1.728 to 3.400, p < 0.001). Cox regression showed no significant difference in mortality between patients ≥80 years with moderate AS compared to a younger age-group ≥70 years with severe AS. In conclusion, very elderly patients of ≥80 years of age with moderate AS have worse prognostic outcomes than their younger counterparts. They share similar unfavorable prognostic outcomes as those of a younger age-group ≥70 years with severe AS. Closer surveillance are warranted in this group of at-risk elderly patients.

An Asia-Pacific study on healthcare workers' perceptions of, and willingness to receive, the COVID-19 vaccination.

OBJECTIVE: In the fight against COVID-19, vaccination is vital in achieving herd immunity. Many Asian countries are starting to vaccinate frontline workers; however, expedited vaccine development has led to hesitancy among the general population. We evaluated the willingness of healthcare workers to receive the COVID-19 vaccine. METHODS: From 12 to 21 December 2020, we recruited 1720 healthcare workers from 6 countries: China, India, Indonesia, Singapore, Vietnam and Bhutan. The self-administrated survey collected information on willingness to vaccinate, perception of COVID-19, vaccine concerns, COVID-19 risk profile, stigma, pro-socialness scale, and trust in health authorities. RESULTS: More than 95% of the healthcare workers surveyed were willing to vaccinate. These respondents were more likely to perceive the pandemic as severe, consider the vaccine safe, have less financial concerns, less stigmatization regarding the vaccine, higher pro-socialness mindset and trust in health authorities. A high perceived pandemic risk index, low vaccine harm index and high pro-socialness index were independent predictors in multivariable analysis. CONCLUSIONS: The majority of healthcare workers in Asia are willing to receive COVID-19 vaccination. Perceived COVID-19 susceptibility, low potential risk of vaccine harm and pro-socialness are the main drivers. These findings may help formulate vaccination strategies in other countries.