Risk scoring system for prediction of contrast-induced nephropathy in patients with pre-existing renal impairment undergoing percutaneous coronary intervention

INTRODUCTION

Baseline renal impairment is the most recognised risk factor for development of contrast-induced nephropathy (CIN) post percutaneous coronary intervention (PCI). We examined the additional risk factors in this high-risk group and aimed to develop a risk model for prediction of CIN.

METHODS

A cohort of 770 consecutive patients with existing impaired renal function (estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2), who received routine prophylactic saline hydration and oral N-acetylcysteine treatment while undergoing PCI between May 2005 to October 2008 in our centre, were enrolled. The study endpoint, CIN, was defined as > 25% increase from baseline creatinine within 48 hours post PCI.

RESULTS

Despite routine prophylaxis, CIN occurred in 11.4% of the patients. Important clinical predictors for CIN were age (odds ratio [OR] 1.59, 95% confidence level [CI] 1.0-2.52, p = 0.049), anaemia with haemoglobin < 11 mg/dL (OR 2.26, 95% CI 1.41-3.61, p = 0.001), post-procedure creatinine kinase rise (OR 1.12, 95% CI 1.07-1.16 for every 500 u/L increase, p < 0.001), systolic hypotension with blood pressure < 100 mmHg (OR 2.53, 95% CI 1.16-5.52, p = 0.016) and higher contrast volume. The incidence of CIN was significantly higher in patients with more severe renal failure (6.3%, 17.4% and 40.8% when eGFR was 40-60, 20-40 and < 20 ml/min/1.73 m2 respectively, p < 0.001). A prediction model was developed based on these findings. The incidence of CIN could vary from 2% to > 50% depending on these additional risk profiles.

CONCLUSION

Patients with impaired renal function undergoing PCI are at high risk of developing CIN despite traditional prophylaxis. A model of risk prediction could be used to predict its occurrence.

Electrocardiography Series. ECGs of structural heart disease: Part 1

Electrocardiogram (ECG) is a useful but imperfect investigation in the diagnosis and possible follow-up of structural heart disease such as ventricular hypertrophy. Different ECG criteria with different sensitivity and specificity are available to aid the detection of left or right ventricular hypertrophy. Subsequent echocardiography can help in the quantification of ventricular mass and identification of the aetiology.

Misleading ECG recordings

Misleading electrocardiogram recordings are not uncommon, and can lead to misdiagnosis. This article highlights two examples and discusses the strategies to recognise them.

Managing ventricular ectopics: are ventricular ectopic beats just an annoyance?

How important are PVCs and what should we do about them? PVCs are not a disease in themselves, but a marker of possible underlying conditions that may increase the risk of cardiac death. They serve as a flag to alert us to exclude structural heart disease, the presence of which is the strongest predictor of adverse events. However, it is important to know that PVCs are common in people with no structural heart disease. In this situation, the prognosis is generally excellent. Suppression of PVCs with antiarrhythmic medication is not indicated routinely, unless the patient is symptomatic or at risk of tachycardia-induced cardiomyopathy owing to the very high frequency of PVCs. Where pharmacological therapy has failed, there is now the option of radiofrequency ablation for elimination of frequent symptomatic PVCs. The ECG is a simple yet useful tool to improve risk assessment, especially in those with known cardiovascular disease.

A cohort study of risk factors and clinical outcome predictors for patients presenting with unstable angina and non ST segment elevation myorardial infraction undergoing coronary intervention

INTRODUCTION

Thrombolysis in Myocardial Infarction (TIMI) score has been used to predict outcomes in patients presenting with unstable angina (UA) and non-ST elevation myocardial infarction (NSTEMI). Our study assessed other clinical predictors for patients with UA/NSTEMI undergoing early percutaneous coronary intervention (PCI).

MATERIALS AND METHODS

A cohort of 3822 patients presented with UA/NSTEMI from June 2001 to March 2008 in our center were recruited. Patients underwent PCI during admission. We analyzed the potential risk predictors for major adverse cardiac events (MACE) and death at 1 month and 6 month.

RESULTS

Median age was 57.1 +/- 11.1, 78.1 percent men, 34.5 percent had diabetes, 58.8 percent had hypertension. Coronary lesions involving left main and proximal left anterior descending artery was 27.6 percent. 36.1 percent had NSTEMI. Significant predictors for mortality at 6 months were age older than 70 years (p = 0.001, OR = 5.5), female gender (p = 0.001, OR = 2.98), anaemia (p < 0.001 OR = 8.47), baseline renal impairment (P < 0.001, OR = 7.38) and development of contrast nephropathy (CIN) which was defined as 25% or 0.5 mg/dl increase from baseline Creatinine within 48 h after PCI (p = 0.005, OR = 5.8). Diabetes was a predictor of MACE at 6 months (p = 0.003, OR = 1.51) but not mortality.

CONCLUSIONS

In patients with UA/NSTEMI, our study showed that MACE and mortality were increased in elderly, female and presence of anaemia. Mortality, but not MACE was increased in chronic renal impairment and development of CIN; while diabetes increased only MACE, but not mortality.

SUMMARY

We analyzed a cohort of 3822 patients with UA/NSTEMI underwent PCI and found that elderly, female, presence of anemia, diabetes and chronic renal impairment were high risk predictors for adverse clinical outcome. In addition, development of CIN increased mortality.

Narrow QRS complex tachycardia presenting as palpitation

Atrial fibrillation is the most common sustained cardiac arrhythmia. The rhythm in atrial fibrillation is irregular. Correct interpretation of the electrocardiogram (ECG) is essential. Atrial flutter can present as regular or irregular narrow QRS complex tachycardia. Knowledge of the ECG features of atrial flutter will help to differentiate it from paroxysmal supraventricular tachycardia. The treatment strategy in atrial fibrillation should focus on rhythm control vs. rate control, and anticoagulation should be started based on the calculated risk of systemic embolisation. Atrial flutter is a unique arrhythmia that has similar management strategies to those of atrial fibrillation; however, radiofrequency ablation is increasingly preferred due to its higher rate of efficacy and safety compared to pharmacological therapy.

Electrocardiography Series. What is the cause of the regular wide QRS complex tachycardia?

Regular broad QRS complex tachycardias may be ventricular in origin or due to supraventricular tachycardia with aberrancy. Antidromic atrioventricular re-entrant tachycardia occurring in Wolff-Parkinson-White syndrome is a third possibility. The electrocardiogram is a key tool for distinguishing these tachycardias, which have differing causes, prognoses and treatment strategies. Ventricular tachycardia may be monomorphic or polymorphic. The management of ventricular tachycardia depends on clinical symptoms and is influenced by the presence of structural heart disease.

Half-dose ezetimibe add-on to statin therapy is effective in improving resistant hyperlipidaemia in Asian patients with ischaemic heart disease

INTRODUCTION

Ezetimibe at full dose (10-mg) is used for lipid lowering. We hypothesised that ezetimibe at half dose is effective in achieving percentage improvement in lipid profile among Asian patients with severe hyperlipidaemia.

METHODS

This was a prospective cohort study conducted between 2006 and 2008. 105 patients with hyperlipidaemia not reaching target level with statin treatment alone were given add-on ezetimibe 5-mg daily treatment. Lipid profiles were compared at pre- and post-ezetimibe therapy.

RESULTS

The mean age of the patients was 56.0 +/- 10.3 years. 79.0 percent were male and 62.9 percent had hypertension, 39 percent had diabetes mellitus with a mean HBA1c of 7.7 percent. 58.1 percent had a history of myocardial infarction. The median simvastatin equivalent dose was 40 (range 5-80) mg. Duration of ezetimibe treatment was 102 +/- 60 days. We observed improvements in total cholesterol (TC) (from 5.31 +/- 1.02 to 4.33 +/- 1.11 mmol/l, 16.4 percent reduction, p-value less than 0.0005), low density lipoprotein (LDL) (from 3.43 +/- 0.87 to 2.52 +/- 0.95 mmol/l, 24.0 percent reduction, p-value less than 0.0005) and TC to LDL ratio (from 4.92 +/-1.42 to 4.03 +/-1.16, 16.2 percent reduction, p-value less than 0.0005). The percentage improvement of lipid profile was comparable to that of the published data based on 10-mg dosing.

CONCLUSION

A 5-mg dose of daily ezetimibe add-on treatment is effective in improving lipid profiles in Asian patients with severe hyperlipidaemia not reaching target with statin monotherapy.

Variations of atrioventricular block

Atrioventricular (AV) block comprises a spectrum of cardiac conduction delays with varying clinical presentations. It is commonly encountered in both hospital as well as ambulatory settings, and recognition of the type of AV conduction delay is essential for appropriate subsequent management. The electrocardiogram is a key tool for identification of patients with AV conduction delays. Contrasting management strategies should be employed for differing levels of conduction block.

Regular narrow complex tachycardia

We discuss cases of paroxysmal supraventricular tachycardia (PSVT), including the patient's presentations and clinical courses. Correct interpretation of electrocardiogram (ECG) and detailed analyses are important in differentiating the various types of PSVT. This is crucial in the immediate and long-term management of these patients.

ECG delta waves in patients with palpitation

It is important to recognise Wolff-Parkinson-White (WPW) syndrome in electrocardiograms (ECG), as it may mimic ischaemic heart disease, ventricular hypertrophy and bundle branch block. In addition, ECG can aid in the localisation of the accessory pathway. Recognising WPW syndrome allows for risk stratification, the identification of associated conditions and the institution of appropriate management.

ECG ST segment elevation in patients with chest pain

We discussed three cases of ST elevation myocardial infarction with ST elevation in the inferoposterior territory and anterior territory, and more uncommonly, concomitant ST elevations in the anterior and inferior electrocardiography (ECG) leads. Correct interpretation of the ECG is crucial in recognising this cardiac emergency, which often necessitates urgent coronary revascularisation. In addition, ECG aids localisation of the infarct-related artery and adds prognostic value.

Contrasting fatty involvement of the right ventricle: lipoma versus lipomatous hypertrophy

We report two rare cases of right ventricular lipomatous involvement, and discuss their contrasting diagnostic images and clinical manifestations. Case 1 is a 21-year-old Malay man who presented with recurrent syncope. Transthoracic echocardiography showed a homogeneous discrete mass attached to the right ventricular septum, occupying the right ventricular outflow tract. Cardiac magnetic resonance (MR) imaging showed features consistent with intracardiac lipoma, which was confirmed on histology, upon surgical resection. Case 2, a 73-year-old Caucasian woman, was found to have incidental lipomatous infiltration of the right ventricle on echocardiography and MR imaging. In contrast to the well-defined right ventricular lipoma seen in the first case, lipomatous involvement was manifested as a diffuse homogeneous thickening of the right ventricular free wall. Multimodality imaging allows for a complementary and detailed characterisation of lipomatous masses involving the ventricular septum.

Diabetic patients with normal baseline renal function are at increased risk of developing contrast-induced nephropathy post-percutaneous coronary intervention

INTRODUCTION

We hypothesised that diabetic patients with normal baseline renal impairment who do not receive prophylaxis before percutaneous coronary intervention (PCI) are at an increased risk of developing contrast-induced nephropathy (CIN).

METHODS

We conducted a cohort study involving 839 patients who underwent PCI between 2004 and 2006, and divided them into three groups: Group A (304 diabetics with normal baseline serum creatinine [Cr] of less than 1.5 mg/dL); Group B (465 non-diabetics with normal Cr); Group C (70 patients with impaired baseline renal function with Cr more than or equal to 1.5 mg/dL). CIN prophylaxis, including oral N-acetylcysteine and saline hydration, were administered only to Group C patients.

RESULTS

The median age for Groups A, B and C was 58, 56 and 64 years, respectively. The prevalence of hypertension in Groups A, B and C was 76.3, 56 and 85.7 percent, respectively. Baseline demographics were comparable among the three groups with regard to gender, left ventricular systolic function and contrast volume use. Incidences of CIN in Groups A, B and C were 8.9 percent, 4.3 percent and 4.5 percent, respectively (p-value is 0.042). The incidence of CIN in diabetic patients with a normal baseline Cr who did not receive prophylaxis (Group A) was significantly higher than in the other two groups (p-value is less than 0.001).

CONCLUSION

Our findings suggest that diabetic patients, despite having a normal baseline Cr, are at an increased risk of developing CIN post-PCI. Routine prophylaxis in this cohort may be beneficial.

Infective endocarditis secondary to intravenous Subutex abuse

INTRODUCTION

Subutex (buprenophine) was approved by the Health Science Authority of Singapore for heroin detoxification in 2002. The number of heroin addicts has decreased in Singapore since the introduction of Subutex. However, Subutex abuse and its associated complications became arising medical problems. We report the management of a series of infective endocarditis cases secondary to Subutex abuse.

METHODS

We identified 12 cases of infective endocarditis in former heroin addicts treated with Subutex from August 2005 to April 2006. All patients were interviewed by the research coordinator and prospectively followed-up for two years.

RESULTS

The treatment period of Subutex endocarditis was often prolonged with a mean hospitalisation stay of 48 days, with 3.8 days in the intensive care unit. Multiple medical complications were noted. Staphylococcus aureus septicaemia accounted for 92 percent of cases. Mortality rate was 42 percent. Failure rate of medical therapy alone was common. 25 percent underwent open heart valve surgery. All patients were subsidised. Mean hospitalisation expenses was S$31,218.

CONCLUSION

Subutex endocarditis causes significant morbidity and mortality. It imposes a heavy medical and financial burden to the patient and society. Multidisciplinary treatment involving cardiologists, infectious disease physicians, psychiatrists, surgeons, medical counsellors and social workers is required to manage these patients.

Isolated high lateral acute myocardial infarction with superior injury current axis

We report a 70-year-old man with high lateral ST elevation myocardial infarction secondary to occlusion of left circumflex artery. Electrocardiography (ECG) showed ST depression in inferior leads and isolated ST elevation in leads aVR and aVL, demonstrating a superior axis of the injury current vector. Different presentations of ECG pattern from left circumflex artery occlusion were discussed. This case highlights the importance of recognising unusual ECG pattern in accurate diagnosis of acute myocardial infarction.

Efficacy of community-based multidisciplinary disease management of chronic heart failure

INTRODUCTION

A multidisciplinary disease management (DM) programme in chronic heart failure (CHF) improves clinical outcome. The efficacy of such a programme in a heterogeneous Asian community is not well established. Therefore, we undertook the evaluation of the efficacy of the multidisciplinary community-based DM CHF programme.

METHODS

This was a prospective study involving 154 patients (54 percent male) with a primary diagnosis of CHF, New York Heart Association functional class III/IV CHF, with left ventricular ejection fraction (LVEF) less than 40 percent. The mean age was 65 +/- 12 years and mean LVEF was 27 +/- 9 percent. We evaluated CHF hospitalisation, quality of life, activity status and quality of care (percentage of patients who received ACE inhibitors/angiotensin receptor blockers (ARB) and beta blockers after a period of six months.

RESULTS

At six months, there was improvement in the quality of life and activity status (p < 0.001). ACE inhibitors/ARB were maintained in 97 percent of the patients and there was an increased usage of beta blockers (p-value equals 0.001). The rate of CHF hospitalisation was reduced by 68 percent (p-value is less than 0.001) and there was no mortality.

CONCLUSION

The multidisciplinary DM of CHF in a heterogeneous Asian community showed significant improvement in quality of life, quality of care and reduction in CHF hospitalisation.

ReoPro Observational Registry (RAPOR): insights from the multicentre use of abciximab in Asia

INTRODUCTION

The pattern of use of abciximab in real-life clinical patients undergoing percutaneous coronary intervention (PCI) in 11 high-volume centres in Singapore, Malaysia, Thailand, Philippines, India, Pakistan and Korea was prospectively examined.

METHODS

These centres enrolled 224 consecutive patients over eight months to receive abciximab during PCI for the study. The cohort consisted of 82.1 percent males, with mean age of 55 (+/- 11) years and mean weight of 67 (+/- 17) kg.

RESULTS

The use of abciximab during PCI ranged between 6.2 percent and 21.6 percent. The indications for the use of abciximab were: acute coronary syndromes (34.3 percent), complex coronary lesions (17.9 percent) and multivessel PCI (17.7 percent). Based on a risk scoring system devised for this registry, majority (60.0 percent) of the patients was considered high risk when abciximab was used. Among the patients enrolled, 36.6 percent received abciximab as a "bail-out". The overall in-hospital ischaemic event rates were low at 4.0 percent. The complication rates included major bleeding 0.7 percent, thrombocytopenia 2.7 percent and need for blood transfusion 2.8 percent. There was a trend towards a higher incidence of in-hospital non-Q myocardial infarction in the "bail-out" group (2.1 percent versus 7.3 percent, p-value equals 0.07).

CONCLUSION

Abxicimab was uncommonly used among patients (9.4 percent) undergoing PCI in this Asian region, with the operators reserving it mainly for high-risk patients.

A case of broken heart from blunt trauma

A young man with blunt chest trauma presented acutely in shock as a result of cardiac rupture causing acute bloody tamponade. We discuss the clinical presentation, the importance of rapid and accurate diagnosis and management of such cases.