Association of face mask use with self-reported cardiovascular symptoms during the COVID-19 pandemic

INTRODUCTION@#Countries are mandating the use of face masks to stem the spread of coronavirus disease 2019 (COVID-19). Face mask use has been associated with discomfort due to its effects on thermoregulation, breathing and oxygenation. We evaluated the prevalence and severity of self-reported cardiovascular symptoms before and during face mask use.@*METHODS@#This was a cross-sectional study of 1,001 participants residing in Singapore, who participated in a self-administered questionnaire between 25 April 2020 and 4 May 2020. Symptom severity before and during mask use, and health-seeking behaviour information were collected. The study outcome was self-reported worsening of cardiovascular symptoms and its association with the type of mask worn, duration of mask worn per day, and intensity of physical activities during mask use.@*RESULTS@#The most common symptom reported during mask use was dyspnoea. Independent predictors for self-reported cardiovascular symptoms during mask use were moderate-high physical activity during mask use (odds ratio [OR] 1.634, 95% confidence interval [CI] 1.176-2.270, P = 0.003), duration of mask use for ≥3 h (OR 1.672, 95% CI 1.189-2.352, P = 0.003) and type of mask used, after adjusting for age, sex, healthcare-based worker status and presence of comorbidities. N95 mask was associated with worse symptoms when compared to surgical mask. Participants with ≥3 worsening symptoms or worsening dyspnoea, palpitations, fatigue and dizziness were more likely to seek medical help.@*CONCLUSION@#Face mask use has been proven to be an effective way in curbing COVID-19 transmission. However, participants in this study had concerns regarding its use and these concerns should be urgently addressed to enable mask use policies to be enacted.

Cost-Effectiveness of Transcatheter Aortic Valve Implantation in Intermediate and Low Risk Severe Aortic Stenosis Patients in Singapore

INTRODUCTION@#Singapore has the world's second most efficient healthcare system while costing less than 5% GDP. It remains unclear whether transcatheter aortic valve implantation (TAVI) is cost-effective for treating intermediate-low risk severe aortic stenosis (AS) patients in a highly efficient healthcare system.@*MATERIALS AND METHODS@#A two-phase economic model combining decision tree and Markov model was developed to assess the costs, effectiveness, and the incremental cost-effectiveness ratio (ICER) of transfemoral (TF) TAVI versus surgical aortic valve replacement (SAVR) in intermediate-low risk patients over an 8-year time horizon. Mortality and complications rates were based on PARTNER 2 trial cohort A and Singapore life table. Costs were mainly retrieved from Singapore National University Health System database. Health utility data were obtained from Singapore population based on the EuroQol-5D (EQ-5D). A variety of sensitivity analyses were conducted.@*RESULTS@#In base case scenario, the incremental effectiveness of TF-TAVI versus SAVR was 0.19 QALYs. The ICER of TF-TAVI was S$33,833/QALY. When time horizon was reduced to 5 years, the ICER was S$60,825/QALY; when event rates from the propensity analysis was used, the ICER was S$21,732/QALY and S$44,598/QALY over 8-year and 5-year time horizons, respectively. At a willingness to pay threshold of S$73,167/QALY, TF-TAVI had a 98.19% probability of being cost-effective after 100,000 simulations. The model was the most sensitive to the costs of TF-TAVI procedure.@*CONCLUSION@#TF-TAVI is a highly cost-effective option compared to SAVR for intermediate-low risk severe AS patients from a Singapore healthcare system perspective. Increased procedure experience, reduction in device cost, and technology advance may have further increased the cost-effectiveness of TF-TAVI per scenario analysis.

Ethnic Differences and Trends in ST-Segment Elevation Myocardial Infarction Incidence and Mortality in a Multi-Ethnic Population

INTRODUCTION@#This study aimed to compare the incidence and mortality of ST-segment elevation myocardial infarction (STEMI) across the 3 main ethnic groups in Singapore, determine if there is any improvement in trends over the years and postulate the reasons underlying the ethnic disparity.@*MATERIALS AND METHODS@#This study consisted of 16,983 consecutive STEMI patients who sought treatment from all public hospitals in Singapore from 2007 to 2014.@*RESULTS@#Compared to the Chinese (58 per 100,000 population in 2014), higher STEMI incidence rate was consistently observed in the Malays (114 per 100,000 population) and Indians (126 per 100,000 population). While the incidence rate for the Chinese and Indians remained relatively stable over the years, the incidence rate for the Malays rose slightly. Relative to the Indians (30-day and 1-year all-cause mortality at 9% and 13%, respectively, in 2014), higher 30-day and 1-year all-cause mortality rates were observed in the Chinese (15% and 21%) and Malays (13% and 18%). Besides the Malays having higher adjusted 1-year all-cause mortality, all other ethnic disparities in 30-day and 1-year mortality risk were attenuated after adjusting for demographics, comorbidities and primary percutaneous coronary intervention.@*CONCLUSION@#It is important to continuously evaluate the effectiveness of existing programmes and practices as the aetiology of STEMI evolves with time, and to strike a balance between prevention and management efforts as well as between improving the outcome of "poorer" and "better" STEMI survivors with finite resources.

Percutaneous pulmonary valve implantation as an alternative to repeat open-heart surgery for patients with pulmonary outflow obstruction: a reality in Singapore

Right ventricle to pulmonary artery (RV-PA) conduits have been used for the surgical repair of congenital heart defects. These conduits frequently become stenosed or develop insufficiency with time, necessitating reoperations. Percutanous pulmonary valve implantation (PPVI) can delay the need for repeated surgeries in patients with congenital heart defects and degenerated RV-PA conduits. We presented our first experience with PPVI and described in detail the procedural methods and the considerations that are needed for this intervention to be successful. Immediate and short-term clinical outcomes of our patients were reported. Good haemodynamic results were obtained, both angiographically and on echocardiography. PPVI provides an excellent alternative to repeat open-heart surgery for patients with congenital heart defects and degenerated RV-PA conduits. This represents a paradigm shift in the management of congenital heart disease, which is traditionally managed by open-heart surgery.

A review of bioresorbable scaffolds: hype or hope?

In the field of percutaneous coronary intervention, the evolution of coronary metal stents has been well established for the past three decades, but research on bioresorbable scaffolds has only gained momentum in the recent past. Although second-generation drug-eluting metal stents are the gold standard for the treatment of obstructive coronary artery disease, a few drawbacks exist. The development of bioresorbable scaffolds is an attempt to overcome the limitations of metal stents. This review highlights the rationale for the bioresorbable scaffold, its properties and potential applications. It also focuses on the current evidence and concerns regarding the application of the bioresorbable scaffold in day-to-day practice.

Mid-term study of transcatheter aortic valve implantation in an Asian population with severe aortic stenosis: two-year Valve Academic Research Consortium-2 outcomes

<p><b>INTRODUCTION</b>Transcatheter aortic valve implantation (TAVI) is an effective treatment for high-risk or inoperative patients with severe aortic stenosis. Given the unique characteristics of Asian populations, questions regarding mid-term outcomes in Asians undergoing TAVI have yet to be addressed. We evaluated the two-year clinical outcomes of TAVI in an Asian population using Valve Academic Research Consortium-2 definitions.</p><p><b>METHODS</b>This prospective study recruited 59 patients from a major academic medical centre in Singapore. The main outcomes were two-year survival rates, peri-procedural complications, symptom improvement, valvular function and assessment of learning curve.</p><p><b>RESULTS</b>Mean age was 76.8 years (61.0% male), mean body surface area 1.6 mand mean logistic EuroSCORE 18.7%. Survival was 93.2%, 86.0% and 79.1% at 30 days, one year and two years, respectively. At 30 days post TAVI, the rate of stroke was 1.7%, life-threatening bleeding 5.1%, acute kidney injury 25.0%, major vascular complication 5.1%, and new permanent pacemaker implantation 6.8%. 29.3% of TAVI patients were rehospitalised (47.1% cardiovascular-related) within one year. These composite outcomes were measured: device success (93.2%); early safety (79.7%); clinical efficacy (66.1%); and time-related valve safety (84.7%). Univariate analysis found these predictors of two-year all-cause mortality: logistic EuroSCORE (hazard ratio [HR] 1.07; p < 0.001); baseline estimated glomerular filtration rate (HR 0.97; p = 0.048); and acute kidney injury (HR 5.33; p = 0.022). Multivariate analysis identified non-transfemoral TAVI as a predictor of cardiovascular-related two-year mortality (HR 14.64; p = 0.008).</p><p><b>CONCLUSION</b>Despite the unique clinical differences in Asian populations, this registry demonstrated favourable mid-term clinical and safety outcomes in Asians undergoing TAVI.</p>

High-grade culprit lesions are a common cause of ST-segment elevation myocardial infarction

<p><b>INTRODUCTION</b>Conventional knowledge holds that the majority of ruptured atherosclerotic plaques causing ST-segment elevation myocardial infarction (STEMI) are found in moderate stenoses that produce < 50% loss of arterial diameter. This study aimed to analyse the culprit lesions in patients who presented with STEMI and underwent primary percutaneous coronary intervention (PPCI) at our institution.</p><p><b>METHODS</b>Patients who underwent PPCI between June 2008 and August 2010 at our institution were included in the analysis. Quantitative coronary angiography was performed for the culprit lesions immediately after antegrade flow was restored by thrombectomy, low-profile balloon predilatation or guidewire crossing.</p><p><b>RESULTS</b>A total of 1,021 patients were included in the study. The mean age was 57 ± 12 years and 85.2% were male. Lesion measurement was done after coronary flow was restored by thrombectomy (73.1%), balloon dilatation (24.1%) and following guidewire passage across the lesion (2.8%). Mean minimal luminal diameter was 1.1 ± 0.5 mm, mean reference vessel diameter was 2.8 ± 0.6 mm, mean diameter stenosis was 61 ± 16% and mean lesion length was 16 ± 6 mm. Most (80.2%) of the culprit lesions had diameter stenoses > 50% (p < 0.01). Although balloon angioplasty was performed in 24.1% of the patients, the majority (64.2%) still had diameter stenoses > 50%. High-grade stenoses (> 50%) were more frequently observed in male patients (p = 0.04).</p><p><b>CONCLUSION</b>Contrary to the existing paradigm, we found that most of the patients with STEMI in our institution had culprit lesions with diameter stenosis > 50%.</p>

Long-term Outcomes of Medical Therapy Versus Coronary Revascularisation in Patients with Intermediate Stenoses Guided by Pressure Wire

<p><b>INTRODUCTION</b>This study aimed to examine the long-term clinical outcomes of coronary fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) in a real-world population in an Asian tertiary centre.</p><p><b>MATERIALS AND METHODS</b>All patients who underwent FFR measurement for intermediate coronary lesions in our centre from June 2002 to December 2009 were enrolled. A threshold of FFR ≤0.75 was used for revascularisation. All the patients were prospectively followed-up for major adverse cardiac events (MACE) of death, myocardial infarction (MI), target vessel revascularisation (TVR) and stent thrombosis.</p><p><b>RESULTS</b>Based on FFR measurement, 368 (57%) patients were treated medically while 278 (43%) underwent revascularisation. At a mean follow-up duration of 29.7 ± 16 months, 53 (14.4%) patients in the medical therapy group and 32 (11.5%) patients in the revascularised group experienced MACE (P = 0.282). There were no statistical differences in all the clinical endpoints between the 2 groups.</p><p><b>CONCLUSION</b>Medical therapy based on FFR measurement is associated with low incidences of MACE at long-term follow-up.</p>

Demographics of severe valvular aortic stenosis in Singapore

<p><b>INTRODUCTION</b>The treatment of aortic valve stenosis (AS) is seeing renewed interest mainly due to the availability of transcatheter therapies. However, the number of epidemiological studies of this disease in Singapore is limited. We aimed to describe the aetiology and clinical presentation of AS in Singapore, as well as patients' attitudes toward it. Our findings may facilitate the future planning and utilisation of resources to better manage these patients.</p><p><b>METHODS</b>249 consecutive patients who underwent transthoracic echocardiography (from April 1999 to April 2008) and diagnosed with severe AS were assessed. Demographic and clinical data were collected, and patients' decisions on surgery were determined.</p><p><b>RESULTS</b>The mean patient age was 71 (range 23-98) years. 50.2% of patients were male. The commonest presenting symptom was dyspnoea, and 40 (16.0%) patients had coexistent atrial fibrillation. The aetiology of AS was degenerative in 216 (86.7%), rheumatic in 11 (4.4%) and related to a bicuspid valve in 22 (8.9%) patients. The average peak velocity across the aortic valve was 4.2 ± 0.8 m/s and the mean aortic valve area was 0.76 ± 0.13 cm2. The overall mean logistic EuroSCORE was 10.7 ± 12.3. 105 (42.2%) patients who were offered surgery refused. 87 (35%) deaths were seen during the follow-up period (mean duration 14.5 months), which also saw 68 (27%) patients undergo surgery and 86 (34%) patients hospitalised for heart failure.</p><p><b>CONCLUSION</b>Degenerative AS was the commonest aetiology in this contemporary cohort of patients. Despite the known benefits of surgery, the refusal rate for surgery remained high.</p>

Angiographic and intravascular ultrasonographic features of Kawasaki coronary artery disease

We report a 38-year-old man with previous Kawasaki disease who presented with exertional dyspnoea and was found to have multivessel coronary aneurysm and stenoses on coronary angiography. Coronary artery bypass surgery was subsequently performed. This case highlights the angiographic and intravascular ultrasonographic imaging features of this relatively uncommon condition presenting to an adult general cardiology service in Singapore.

Management of acute ST-elevation myocardial infarction: Reperfusion options

Primary percutaneous coronary intervention and thrombolysis remain therapies of choice for patients presenting with ST-segment elevation myocardial infarction (STEMI). Clinical outcome in the management of acute STEMI is dependent on myocardial reperfusion time and reperfusion strategies. Optimisation of these strategies should take into consideration logistical limitations of the local medical systems and the various patient profiles. We review the reperfusion strategies and its history in Singapore, comparing its clinical application with that in some developed Western countries.

Risk factors and clinical outcomes for contrast-induced nephropathy after percutaneous coronary intervention in patients with normal serum creatinine

<p><b>INTRODUCTION</b>We aim to examine the risk predictors of contrast-induced nephropathy (CIN) in patients with normal baseline serum creatinine (Cr). CIN is an important complication postpercutaneous coronary intervention (PCI). Previous studies examined CIN predictors in patients with chronic renal impairment. No large studies investigated patients with normal renal function which constitute the majority undergoing PCI. We aim to identify risk predictors in this cohort and examine the clinical outcomes.</p><p><b>MATERIALS AND METHODS</b>A total of 3036 patients with normal baseline Cr (<1.5 mg/dL) who did not receive prophylaxis while undergoing PCI were enrolled. We examined the occurrence of CIN and the mortality outcome at 1 and 6 months.</p><p><b>RESULTS</b>CIN occurred in 7.3% of patients. The median age was 59.5 years (range, 26 to 86), 78.7% men, 34.6% diabetics. Risk predictors for CIN include age [odds ratio (OR), 6.4; 95% CI, 1.01-13.3; P = 0.042], female gender (OR, 2.0; 95% CI, 1.5-2.7; P = 0.001), abnormal left ventricular ejection fraction (LVEF) <50%(OR,1.02; 95% CI, 1.01-1.04; P = 0.01), anaemia with haemoglobin <11 mg/dL (OR, 1.5; 95% CI, 1.01-2.4; P = 0.044) and systolic hypotension with blood pressure <100 mmHg (OR, 1.5; 95% CI, 1.01-2.2; P = 0.004). Diabetics on insulin therapy were at the highest risk compared with diabetics on oral hypoglycaemics and diet control (18.9% vs 6.8% vs 3.6%; P = 0.001). Patients who developed CIN had higher mortality at 1 month (14.5% vs 1.1%; P <0.001) and 6 months (17.8% vs 2.2%; P <0.001).</p><p><b>CONCLUSIONS</b>Subgroups of patients with normal baseline Cr undergoing PCI are at risk of developing CIN with resultant higher mortality. Age, female gender, insulin dependent diabetes mellitus, presence of hypotension, anaemia and low LVEF are predictors of CIN. Prophylaxis may be considered in these patients.</p>

Eighteen-month clinical safety and efficacy outcomes of sirolimus-, paclitaxel- and zotarolimus-drug eluting stents in diabetic patients undergoing percutaneous coronary intervention for complex coronary artery stenosis

<p><b>INTRODUCTION</b>This was a single centre registry study on clinical efficacy and safety of drug-eluting stent (DES) in diabetic patients undergoing percutaneous coronary intervention (PCI) for complex coronary lesions.</p><p><b>MATERIALS AND METHODS</b>A total of 288 diabetic patients who underwent elective PCI between September 2003 and June 2006 in our centre were enrolled and followed-up for 18 months. Among them, 79 (27.4%) patients received sirolimus-eluting stent (SES), 138 (47.9%) paclitaxel-eluting stent (PES) and 71 (24.7%) zotarolimus-eluting stent (ZES). The endpoints were major adverse cardiac events (MACE) and stent thrombosis rates.</p><p><b>RESULTS</b>Baseline demographics were comparable among the 3 DES groups (median age was 60 years; 69% men). Complex lesions (defined as ACC/AHA type C stenosis) accounted for 55.6% of the total lesions: SES (50.6%), PES (65.2%) and ZES (43.7%), P = 0.005. At 18 months follow-up, the composite endpoint of MACE was found in 12.7% in SES group, 8.7% in the PES group, 12.7% in ZES group and (P = 0.55). Stent thrombosis (ST) occurred in 1 patient (1.3%) in the SES group, 2 patients (1.4%) in PES group and 1 patient (1.4%) in ZES group, respectively (P = 1.00).</p><p><b>CONCLUSION</b>The use of DES for elective PCI in diabetic patients was associated with favourable intermediate-term clinical outcomes with no significant differences in efficacy among the 3 groups. Stent thrombosis had low event occurrence rate.</p>

The impact of gender on the outcomes of invasive versus conservative management of patients with non-ST-segment elevation myocardial infarction

<p><b>INTRODUCTION</b>Studies have suggested that women who present with non-ST-segment elevation myocardial infarction (NSTEMI) may differ in their clinical response to early invasive strategy compared to male patients. We examined the impact of gender difference in NSTEMI patients on outcomes following invasive versus conservative treatment.</p><p><b>MATERIALS AND METHODS</b>Patients enrolled in our national myocardial infarction (MI) registry between January 2000 and September 2005 with diagnosis of NSTEMI were retrospectively analysed. The study endpoint was the occurrence of major adverse cardiac events (MACE) in the patients at 1 year.</p><p><b>RESULTS</b>A total of 1353 patients (62.2% male) with NSTEMI were studied. The mean age of men was 62 +/- 14 versus 72 +/- 12 years in women in the cohort (P <0.001). The prevalence of hypertension and diabetes mellitus were significantly higher in women. Men were more likely to undergo revascularisation than women (OR, 2.97; 95% CI, 2.18-3.89, P <0.001). Among those who were revascularised, there was no gender difference in survival or recurrent MI rates during hospitalisation and at 1 year. Compared to medical therapy, percutaneous coronary intervention (PCI) was associated with a significant reduction in MACE in both women (OR, 0.44; 95% CI, 0.20-0.95) and men (OR, 0.40; 95% CI, 4.79-12.75). The most important predictor of MACE for females was diabetes mellitus (HR, 1.98; 95% CI, 1.17-3.33).</p><p><b>CONCLUSIONS</b>There is a gender-based difference in the rate of revascularisation among patients with NSTEMI. Women benefit from an invasive approach as much as men, despite their advanced age, with similar rates of mortality and recurrent MI at 1-year follow-up.</p>

Reperfusion strategy and mortality in ST-elevation myocardial infarction among patients with and without impaired renal function

<p><b>INTRODUCTION</b>Several randomised controlled trials have demonstrated better outcomes with primary percutaneous coronary intervention (PCI) over fibrinolytic therapy in the treatment of patients with ST-segment elevation myocardial infarction (STEMI) and normal renal function. Whether this benefit extends to patients with impaired renal function is uncertain.</p><p><b>MATERIALS AND METHODS</b>We studied 1672 patients with STEMI within 12 hours of symptom onset who were admitted to 2 major public hospitals in Singapore from 2000 to 2002. All patients received either upfront fibrinolytic or PCI as determined by the attending cardiologist. Serum creatinine was measured on admission and the glomerular filtration rate (GFR) was determined using the Modification of Diet in Renal Disease equation. The impact of reperfusion strategy on 30-ay mortality was then determined for patients with GFR > or =60 mL min-(1) 1.73 m-(2) and GFR <60 mL min-(1) 1.73 m-(2).</p><p><b>RESULTS</b>The mean age was 56 +/- 12 years (85% male) and mean GFR was 81 +/- 30 mL min-(1) 1.73 m-(2). Unadjusted 30-day mortality rates for fibrinolytic-treated vs primary PCI-treated patients were 29.4% vs 17.9%, P <0.05, in the impaired renal function group and 5.4% vs 3.1%, P <0.05, in the normal renal function group. After adjusting for covariates, primary PCI was associated with a significantly lower mortality in the normal renal function group [odds ratio (OR), 0.41; 95% confidence interval (CI), 0.19-0.89] but not in the impaired renal function group [OR, 0.70; 95% CI, 0.31-1.60].</p><p><b>CONCLUSIONS</b>Primary PCI was associated with improved 30-day survival among patients with normal renal function but not among those with impaired renal function. Randomised trials are needed to study the relative efficacy of both reperfusion strategies in patients with impaired renal function.</p>