Impact of Chronic Kidney Disease on Outcomes in Transcatheter Aortic Valve Implantation

INTRODUCTION@#Chronic kidney disease (CKD) is a significant comorbidity in aortic stenosis (AS) patients. We examined the impact of baseline CKD, postoperative acute kidney injury (AKI) and CKD progression on clinical outcomes in patients who underwent transcatheter aortic valve implantation (TAVI).@*MATERIALS AND METHODS@#Consecutive patients with severe AS who underwent TAVI were classified into CKD stages 1-2 (≥60 mL/min/1.72m), 3 (30-59 mL/min/1.73m) and 4-5 (<30 mL/min/1.73m or dialysis) based on estimated glomerular filtration rate (eGFR). Primary outcome was mortality and secondary outcomes included 1-year echocardiographic data on aortic valve area (AVA), mean pressure gradient (MPG) and aortic regurgitation (AR).@*RESULTS@#A total of 216 patients were included. Higher eGFR was associated with lower overall mortality (adjusted hazards ratio [AHR] 0.981, 95% confidence interval [CI] 0.968-0.993, = 0.002). CKD 4-5 were associated with significantly higher mortality from non-cardiovascular causes ( <0.05). Patients with CKD 3-5 had higher incidence of moderate AR than those with CKD 1-2 ( = 0.010); no difference in AVA and MPG was seen. AKI patients had higher mortality ( = 0.008), but the effect was attenuated on multivariate analysis (AHR 1.823, 95% CI 0.977-3.403, = 0.059). Patients with CKD progression also had significantly higher mortality (AHR 2.969, 95% CI 1.373-6.420, = 0.006).@*CONCLUSION@#CKD in severe AS patients undergoing TAVI portends significantly higher mortality and morbidity. Renal disease progression impacts negatively on outcomes and identifies a challenging subgroup of patients for optimal management.

Clinical Updates on the Diagnosis and Management of Chronic Thromboembolic Pulmonary Hypertension

INTRODUCTION@#Chronic thromboembolic pulmonary hypertension (CTEPH) is a known sequela after acute pulmonary embolism (PE). It is a debilitating disease, and potentially fatal if left untreated. This review provides a clinically relevant overview of the disease and discusses the usefulness and limitations of the various investigational and treatment options.@*METHODS@#A PubMed search on articles relevant to PE, pulmonary hypertension, CTEPH, pulmonary endarterectomy, and balloon pulmonary angioplasty were performed. A total of 68 articles were found to be relevant and were reviewed.@*RESULTS@#CTEPH occurs as a result of non-resolution of thrombotic material, with subsequent fibrosis and scarring of the pulmonary arteries. Risk factors have been identified, but the underlying mechanisms have yet to be fully elucidated. The cardinal symptom of CTEPH is dyspnoea on exertion, but the diagnosis is often challenging due to lack of awareness. The ventilation/perfusion scan is recommended for screening for CTEPH, with other modalities (eg. dual energy computed tomography pulmonary angiography) also being utilised in expert centres. Conventional pulmonary angiography with right heart catheterisation is important in the final diagnosis of CTEPH.@*CONCLUSION@#Operability assessment by a multidisciplinary team is crucial for the management of CTEPH, as pulmonary endarterectomy (PEA) remains the guideline recommended treatment and has the best chance of cure. For inoperable patients or those with residual disease post-PEA, medical therapy or balloon pulmonary angioplasty are potential treatment options.

Ministry of Health Clinical Practice Guidelines: Hypertension

The Ministry of Health (MOH) has updated the clinical practice guidelines on hypertension to provide doctors and patients in Singapore with evidence-based treatment for hypertension. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on hypertension, for the information of SMJ readers. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/content/moh_web/healthprofessionalsportal/doctors/guidelines/cpg_medical.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Percutaneous transcatheter aortic valve implantation for degenerated surgical bioprostheses: the first case series in Asia with one-year follow-up

<p><b>INTRODUCTION</b>Percutaneous transcatheter aortic valve implantation (TAVI) has become an established therapy for inoperable and high-surgical-risk patients with severe aortic stenosis. Although TAVI in patients with degenerated surgical aortic bioprostheses (i.e. valve-in-valve TAVI) is increasingly reported in Western studies, such data is lacking in Asian patients. We describe the initial experience of valve-in-valve TAVI in Asia.</p><p><b>METHODS</b>Eight patients who underwent valve-in-valve TAVI due to degenerated aortic bioprostheses were enrolled. The mechanism of bioprosthetic valve failure was stenotic, regurgitation or mixed. All procedures were performed via transfemoral arterial access, using the self-expanding CoreValve prosthesis or balloon-expandable SAPIEN XT prosthesis.</p><p><b>RESULTS</b>The mean age of the patients was 71.6 ± 13.2 years and five were male. Mean duration to surgical bioprosthesis degeneration was 10.2 ± 4.1 years. Valve-in-valve TAVI was successfully performed in all patients. CoreValve and SAPIEN XT prostheses were used in six and two patients, respectively. There were no deaths, strokes or permanent pacemaker requirement at 30 days, with one noncardiac mortality at one year. All patients experienced New York Heart Association functional class improvement. Post-procedure mean pressure gradients were 20 ± 11 mmHg and 22 ± 8 mmHg at 30 days and one year, respectively. Residual aortic regurgitation (AR) of more than mild severity occurred in one patient at 30 days. At one year, only one patient had mild residual AR.</p><p><b>CONCLUSION</b>In our experience of valve-in-valve TAVI, procedural success was achieved in all patients without adverse events at 30 days. Good clinical and haemodynamic outcomes were sustained at one year.</p>

Electrocardiographic changes in acute perimyocarditis

Pericarditis and myocarditis are characterised by electrocardiographic changes and elevated cardiac enzymes, respectively, and patients with perimyocarditis often complain of chest discomfort. These findings are nonspecific and often lead to diagnostic difficulties, as ST-elevation myocardial infarction commonly presents in a similar fashion. Clinical differentiation between perimyocarditis and myocardial infarction are especially important because adverse side effects can occur if reperfusion therapy is administered for a patient with acute pericarditis or if a diagnosis of acute myocardial infarction is missed. We herein describe a case of perimyocarditis with ST elevation and raised cardiac markers, which led to two emergency coronary angiographies that were subsequently found to be normal. We include the three serial electrocardiographies (ECGs) performed to show the characteristic features of perimyocarditis and further discuss the importance of identifying typical and atypical ECG features of pericarditis.

Percutaneous mitral valve repair with MitraClip for severe functional mitral regurgitation

A 67-year-old Chinese woman with comorbidities of chronic obstructive lung disease, hypertension and prior coronary artery bypass surgery presented with severe functional mitral regurgitation (MR) and severely depressed left ventricular function. She was in New York Heart Association (NYHA) Class II-III. Due to high surgical risk, she was referred for percutaneous treatment with the MitraClip valve repair system. This procedure is typically performed via the femoral venous system and involves a transseptal puncture. A clip is delivered to grasp the regurgitant mitral valve leaflets and reduce MR. This was performed uneventfully in our patient, with reduction of MR from 4+ to 1+. She was discharged on post-procedure Day 2 and her NYHA class improved to Class I. This was the first successful MitraClip procedure performed in Asia and represents a valuable treatment option in patients with severe MR, especially those with functional MR or those at high surgical risk.

Risk assessment models in acute coronary syndromes and their applicability in Singapore

Risk prediction models are critical in managing patients with acute coronary syndromes (ACS) as they identify high-risk patients who benefit the most from targeted care. We discuss the process of developing and validating a risk prediction model as well as highlight the more commonly used models in clinical practice currently. Finally we conclude by outlining the importance of creating a risk prediction model based on a Singapore population of ACS patients so as to further improve patient, hospital and research outcomes.

Complete atrioventricular block complicating acute anterior myocardial infarction can be reversed with acute coronary angioplasty

<p><b>INTRODUCTION</b>A retrospective case series of acute anterior myocardial infarction (MI) patients complicated by complete atrioventricular block (AVB) treated with acute percutaneous transluminal coronary angioplasty (PTCA).</p><p><b>CLINICAL PICTURE</b>Eight patients with anterior MI and complete AVB underwent acute PTCA between 2000 and 2005. Mean onset of complete AVB was 16.6 +/- 16.9 hours from chest pain onset.</p><p><b>TREATMENT</b>All patients underwent successful PTCA to the left anterior descending artery.</p><p><b>OUTCOME</b>Complete AVB resolved with PTCA in 88%; mean time of resolution was 89 +/- 144 minutes after revascularisation. One patient had permanent pacemaker implanted at Day 12 after developing an 8-second ventricular standstill during hospitalisation but not pacing-dependent on follow-up. The rhythm on discharge for the other surviving patients was normal sinus rhythm.</p><p><b>CONCLUSION</b>This case series suggests that complete AVB complicating anterior MI is reversible with acute PTCA and survivors are not at increased risk of recurrent AVB. Nevertheless, this condition is associated with extensive myocardial damage and high mortality during the acute hospitalisation was not improved with correction of AVB with temporary pacing.</p>

Stent-assisted percutaneous angioplasty for extra-cranial carotid disease:experience at Singapore General Hospital

<p><b>INTRODUCTION</b>This study aims to analyse the results of carotid stenting in a tertiary referral centre in Singapore.</p><p><b>MATERIALS AND METHODS</b>Retrospective analysis of all carotid artery stenting (CAS) cases in a single centre from March 1997 to December 2008 was performed. Sixty successful procedures were performed in 61 patients, with bilateral stenting in 1 patient, and 2 failed procedures. The majority were Chinese (78.7%) and males (77.0%), with a high proportion having hypertension (82.0%) and hypercholesterolaemia (78.7%). The majority (91.8%) of patients were high surgical risk candidates, primarily due to cardiac risk factors. Ten patients (16.4%) had prior neck irradiation for nasopharyngeal carcinoma, and 3 patients each (4.9%) had previous endarterectomy and contralateral occlusion. A distal embolic protection device was used in 71.7% of cases.</p><p><b>RESULTS</b>Technical success was 96.8%. The 30-day stroke and death rate was 13.8%, comparable to reported results for this high surgical risk population.</p><p><b>CONCLUSION</b>CAS is a technically feasible and a relatively safe alternative to endarterectomy to treat extracranial carotid stenosis, especially in patients who are inoperable or at high surgical risk.</p>