Bacteraemia in ventricular assist devices: a common complication that need not affect clinical outcomes.

BACKGROUND: Ventricular assist device (VAD) implantation has become an effective option for patients with severe heart failure. However, device-related infections remain a significant problem. The aim of this study was to describe the incidence and microbiological aetiology of bacteraemia in patients with VADs, and to assess the impact of bacteraemia on clinical outcomes. METHODS: A retrospective study was conducted of patients having VAD implantation at the Alfred Hospital (Melbourne, Australia) from October 1990 to July 2009. Medical records and microbiology databases were reviewed. Patients who were supported with a VAD for 72h or more were evaluated for demographic data, VAD type, the occurrence of bacteraemia and clinical outcomes. RESULTS: During the 19-year period, 135 VAD patients (89 Thoratec PVAD, 10 Novacor, and 36 Ventrassist) supported for a total duration of 17,304 (median 74) support days were included. Sixty-one patients (45%) developed VAD-associated bacteraemia, an incidence of 5.6 episodes per 1000 support days. The incidence of bacteraemia per 1000 days of support was similar for the three devices used: Thoratec PVAD, Novacor and Ventrassist VADs (7.8±0.8, 5.2±1.5 and 3.4±0.5, respectively, p=0.74). Staphylococcus aureus was the most common pathogen (25%). The rates of death on device, survival to transplant, recovery with explant and outcomes after transplantation, including 30-day mortality, median survival time and incidence of cerebrovascular accidents were not significantly impacted upon by bacteraemia. CONCLUSIONS: Bacteraemia is common in VAD patients. However, the incidence of VAD-associated bacteraemia is independent of device type and with aggressive antimicrobial therapy; clinical outcomes need not be affected by the bacteraemia.

Effect of renin angiotensin system inhibitors on long-term major cardiovascular outcomes in patients with high atherosclerotic cardiovascular risk.

The advantage of angiotensin converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) in patients with preserved LV systolic function is uncertain. We aimed to investigate the effects of ACEI/ARB in high atherosclerotic risk patients without overt heart failure (HF) on long-term major cardiovascular outcomes (MACEs). The Cohort Of patients with high Risk for cardiovascular Events (CORE-Thailand) registry is a prospective, multicenter, observational, longitudinal study of Thai patients with high atherosclerotic risk. The patients with ejection fraction < 50% were excluded. Among 8513 recruited patients, there were 4246 patients included into final analysis after propensity score matching. At 5-years follow-up, Cox regression analysis showed that ACEI/ARB was significantly associated with reduced risk of all-cause mortality or non-fatal myocardial infarction, non-fatal stroke and HF hospitalization (HR 0.82, 95% CI 0.70-0.96, P = 0.011). The benefit was driven by the reduced all-cause mortality and HF. Subgroup analysis demonstrated that ACEI/ARB decreased risk of long-term MACEs in patients with diabetes (HR 0.77, 95% CI 0.63-0.94, P = 0.011) and patients not taking statin (HR 0.57, 95% CI 0.40-0.82, P = 0.002). We demonstrated that the use of ACEI/ARB was associated with reduced risk of long-term MACEs in a large cohort of high atherosclerotic risk patients. Reduction of all-cause mortality and HF were likely the main contributors to the benefit of ACEI/ARB.

Cardiac myxoma: sixteen-year experience in Central Chest Institute of Thailand.

BACKGROUND: Among the rare diseases of primary cardiac tumor myxoma is a leading pathology. A sixteen-year clinical experience and follow-up ofpatients with surgical removal of this particular mass is reported. MATERIAL AND METHOD: Medical records of intracardiac tumor patients between April 1995 and June 2012 were reviewed and only cardiac myxoma patients who underwent surgical resection were studied The data of clinical presentations, investigations, operative details, and results were analyzed. RESULTS: Forty-five cardiac myxoma patients with a mean age of 52.6 +/- 2.3 (14 to 82) years were on operated during the sixteen-year period; of these, 76% were female. Dyspnea was the most common symptom accounting for approximately 78%,followed by heart failure 38%, and stroke 18%. Constitutional symptoms of weight loss, fatigue, and fever were found 33%, 13%, and 11%, respectively. Mean ejection fraction was 62% and the tumor size varied from 1.4 to 10 centimeters in diameter Site distribution of tumors were left atrium (89%), right atrium (9%), and multiple site (2%), with the interatrial septum as the most frequent site of attachment (69%). Patients with irregular surface tumors had 29% greater chance of having stroke than those with smooth surface tumors (p = 0.015). There was no operative or post-operative mortality. The complete follow-up was 98% with 99.8 +/- 52 months of mean follow-up. Ten and fifteen-year survival were 97%. A recurrence was found in one patient with multiple site tumors at eight-year follow-up. CONCLUSION: Myxoma is a rare disease with a variety of clinical presentation. Surgical resection provides excellent operative and long-term survival. Despite a very insignificant chance of recurrence, long-term follow-up is still necessary.

Left ventricular function after permanent pacemaker in pacemaker clinic follow-up.

BACKGROUND: Chronic right ventricular pacing has deleterious effects to left ventricular function which may be asymptomatic. Prevalence of LV dysfunction (LVEF < 50%) in RV pacing in Thai patients is not known. MATERIAL AND METHOD: Patients in the Central Chest Institute of Thailand (CCIT) pacemaker clinic were retrospectively reviewed for their demographic and pacemaker data together with echocardiographic data for LV function. Analysis was done for those who were implanted for more than one year period. RESULTS: Among the studied 118patients, male = 51 and female = 67, mean follow-up time 6.43 +/- 5.66 years, LV systolic dysfunction was identified in 21 (17.80%). Compared to those with no LV dysfunction, echocardiographic parameters showed larger LVsize (EDD 49.86 +/- 8.95 vs. 43.81 +/- 5.56 mm) and less thickness of the LV wall (11.05 +/- 1.60 vs. 12.49 +/- 2.79 mm). Studied clinical and pace parameters for correlation were hypertension (p = 0.048), coronary artery disease (p = 0.008), percent of ventricular pacing (p = 0.06), duration after implantation (p = 0.23), mode of pacing (p = 0.275), indication of implantation (p = 0.32, site of pacing lead (p = 0.279), moderate to severe MR (p = 0.003) and moderate to severe TR (p = 0.04). CONCLUSION: LV dysfunction after pacemaker implantation was not infrequent. Parameters correlated to it were previous LV dysfunction, hypertension, coronary artery disease and increased amount of ventricular pacing. Mode of pacing and site of pacing lead were not correlated.

Impact of right ventricular pacing on right ventricular function.

BACKGROUND: The benefits of right ventricular pacing in patients with symptomatic bradycardia are well recognized. Currently, left ventricular (LV) function after cardiac pacing has already been extensively investigated. However existing data on right ventricular (RV) function in these patients is extremely limited. MATERIAL AND METHOD: To test this, records of RV and tricuspid valve function of patients with a pacemaker measured at least a year after implantation were reviewed for a prevalence of RV dysfunction. The patients were also divided into those with and without RV dysfunction. Factors affecting the two groups were evaluated. RESULTS: RV dysfunction and moderate to severe tricuspid valve regurgitation were found in approximately 4% and 21% respectively in cardiac pacing patients with mean implantation duration of 6.4 years. Compared to normal RV function, factors presumed to affect on RV dysfunction including site of pacing, pacing mode and percentage of ventricular pacing were not significantly different (p = 0.54, 0.37 and 0.12 respectively). CONCLUSION: Based on these data, the prevalence of right ventricular dysfunction appears to be infrequent and factors that were assumed as contributors to LV dysfunction failed to show significant contributions to RV dysfunction.

Immediate, short and intermediate results of transcatheter closure of secondum-type atrial septal defect using Amplatzer septal occluder devices.

OBJECTIVES: To study the immediate, short, and intermediate results of transcatheter closure of secondum-type atrial septal defect using Amplatzer septal occluder devices (TCAA) in terms of clinical symptoms and residual lesions and shunts determined by transthoracic two-dimensional (TTE) and three-dimensional echocardiography (TDE). MATERIAL AND METHOD: Thirty-six patients, who underwent successful TCAA at the Chest Disease Institute between August 2002 and August 2007 and were followed up clinically, by TTE and TDE at day 1-3, 4-6 months, and 1-year post TCAA, were analyzed. RESULTS: TCAA was performed in 75 patients during the study period. Of these, 36 patients were completely followed-up. There were 92% female with a mean age of 40 +/- 16 yrs (range 19 to 65) and the mean of maximal size of ASD secondum determined by TTE, transesophageal echocardiography (TTE) and balloon sizing or balloon stretched diameter (BSD)was 18.9 +/- 4.7 mm (range 10-30), 22.6 +/- 5.3 mm (rang 10-32), and 24.3 +/- 5.3 mm (range 12-34) respectively. The size of ASOD was 26.4 +/- 4.9 mm (range 12-34). Fluoroscopic time was 16.4 +/- 7.1 min (range 6.7-35.6). The success rate of TCAA was 84%. No major complications and deaths were found. All of those with successful TCAA apparently improved their functional class. All of them showed complete ASD closure and yet 12 (31%) had Qp/Qs > or = 1.5 at year one. CONCLUSION: TCAA is safe and effective and had resulted in clinical improvement, complete closure of secondum ASD, and good immediate, short, and intermediate outcomes with fewer complications.

Short- and long-term outcomes of intracoronary and endogenously mobilized bone marrow stem cells in the treatment of ST-segment elevation myocardial infarction: a meta-analysis of randomized control trials.

AIMS: Bone marrow stem cell (BMSC) treatment of ST-segment elevation myocardial infarction (STEMI) has been primarily via the intracoronary route or via endogenous mobilization using granulocyte colony-stimulating factor (G-CSF). Studies have provided conflicting results. We therefore performed a meta-analysis of these treatments, examining short- and long-term efficacy and safety. METHODS AND RESULTS: Randomized controlled trials (RCTs) of BMSC-based therapy for STEMI, delivered within 9 days of reperfusion, were identified by systematic search. Random effects models were used to calculate pooled effects of clinical outcomes, with meta-regression to assess dependence of the magnitude of effect sizes on study characteristics. Twenty-nine RCTs enrolling 1830 patients were included. Intracoronary BMSC therapy resulted in an overall improvement in left ventricular ejection fraction (LVEF) of 2.70% [95% confidence interval (CI) 1.48-3.92; P < 0.001] in the short term and 3.31% (95% CI 1.87-4.75; P < 0.001) longer term. Meta-regression suggested a dose-response relationship between quantity of CD34(+) cells delivered and increase in LVEF (P = 0.007). G-CSF treatment resulted in a trend towards similar benefits (P = 0.20). No significant differences were observed in pooled adverse outcome rates between intervention and control groups of either treatment approach, except for lower revascularization rates with intracoronary BMSC vs. control (odds ratio 0.68, 95% CI 0.47-0.97; P = 0.03). CONCLUSIONS: Intracoronary BMSC therapy post-STEMI improves LVEF beyond standard medical treatment, in both the short and longer term. G-CSF treatment shows positive but non-significant trends. Both treatments demonstrate safety comparable with conventional medical treatment.

Impact of heart failure and changes to volume status on liver stiffness: non-invasive assessment using transient elastography.

AIM: The impact of cardiac dysfunction on the liver is known as cardiac hepatopathy. In certain instances this can result in significant hepatic fibrosis or cirrhosis. The validity of non-invasive tools to assess hepatic fibrosis, such as FibroScan(®) which measures liver stiffness (LSM), has not been established in this setting. We examined the impact of cardiac dysfunction on LSM using FibroScan(®) and the influence of volume changes on LSM. METHODS AND RESULTS: A prospective, cross-sectional study examined the use of FibroScan(®) in subjects with left-sided heart failure (LHF, n = 32), right-sided heart failure (RHF, n = 9), and acute decompensated heart failure (ADHF, n = 8). The impact of volume changes upon LSM was further examined in the ADHF group (pre- and post-diuresis) and in a haemodialysis group (HD, n = 12), pre- and post-ultrafiltration on dialysis. Compared with healthy controls [n = 55, LSM = median 4.4 (25th percentile 3.6, 75th percentile 5.1) kPa], LSM was increased in all the cardiac dysfunction subgroups [LHF, 4.7 (4.0, 8.7) kPa, P = 0.04; RHF, 9.7 (5.0, 10.8) kPa, P < 0.001; ADHF, 11.2 (6.7, 14.3) kPa, P < 0.001]. Alteration in volume status via diuresis did not change the baseline LSM in ADHF [11.2 (6.7, 14.3) to 9.5 (7.3, 21.6) kPa, P > 0.05] with mean diuresis 5051 ± 1585 mL, or ultrafiltration in HD [6.0 (3.6, 5.1) vs. 5.7 (4.8, 7.0) kPa, P > 0.05] with mean diuresis 1962 ± 233 mL. CONCLUSION: Our findings support the concept of increased LSM in the cardiac failure population. LSM was not altered to a statistically significant level with acute volume changes.

Is target dose of beta-blocker more important than achieved heart rate or heart rate change in patients with systolic chronic heart failure?

Beta-blockers (BBs) are mandatory therapy for patients with systolic chronic heart failure (CHF). However, it is uncertain whether target dose of these agents is more important than the achievement of target heart rate (HR) in maximizing the benefits of these agents. To test this, we obtained ECG absolute HR from patients with systolic CHF, together with consecutive left ventricular ejection fraction (EF) measures at least 3 months apart. Patients were divided into those who achieved target dose for beta-blocker and/or target absolute HR of < or = 60 beats per minute (bpm) and target change in HR (>10 bpm reduction) with increasing dose. Baseline ejection fraction (EF) was similar across all groups. Patients with absolute or change in HR at target achieved a greater change in EF than those not at target (P= 0.027 and P= 0.012, respectively). In contrast, those who achieved target dose did not achieve a significantly greater improvement in EF than those not at target dose (P= 0.81). Similarly for absolute EF, patients at target HR or target change in HR achieved a greater EF increase than those achieving target dose. Based on these data, target HR or change in HR appears to be more critical to improvement in EF than target dose in CHF patients. Therefore, achieving an absolute HR or change in HR with BBs may be more important than target dose in maximizing benefits of BBs in this setting.

B-type natriuretic peptide-guided heart failure therapy: A meta-analysis.

BACKGROUND: The use of plasma levels of B-type natriuretic peptides (BNPs) to guide treatment of patients with chronic heart failure (HF) has been investigated in a number of randomized controlled trials (RCTs). However, the benefits of this treatment approach have been uncertain. We therefore performed a meta-analysis to examine the overall effect of BNP-guided drug therapy on cardiovascular outcomes in patients with chronic HF. METHODS: We identified RCTs by systematic search of manuscripts, abstracts, and databases. Eligible RCTs were those that enrolled more than 20 patients and involved comparison of BNP-guided drug therapy vs usual clinical care of the patient with chronic HF in an outpatient setting. RESULTS: Eight RCTs with a total of 1726 patients and with a mean duration of 16 months (range, 3-24 months) were included in the meta-analysis. Overall, there was a significantly lower risk of all-cause mortality (relative risk [RR], 0.76; 95% confidence interval [CI], 0.63-0.91; P = .003) in the BNP-guided therapy group compared with the control group. In the subgroup of patients younger than 75 years, all-cause mortality was also significantly lower in the BNP-guided group (RR, 0.52; 95% CI, 0.33-0.82; P = .005). However, there was no reduction in mortality with BNP-guided therapy in patients 75 years or older (RR, 0.94; 95% CI, 0.71-1.25; P = .70). The risk of all-cause hospitalization and survival free of any hospitalization was not significantly different between groups (RR, 0.82; 95% CI, 0.64-1.05; P = .12 and RR, 1.07; 95% CI, 0.85-1.34; P = .58, respectively). The additional percentage of patients achieving target doses of angiotensin-converting enzyme inhibitors and beta-blockers during the course of these trials averaged 21% and 22% in the BNP group and 11.7% and 12.5% in the control group, respectively. CONCLUSIONS: B-type natriuretic peptide-guided therapy reduces all-cause mortality in patients with chronic HF compared with usual clinical care, especially in patients younger than 75 years. A component of this survival benefit may be due to increased use of agents proven to decrease mortality in chronic HF. However, there does not seem to be a reduction in all-cause hospitalization or an increase in survival free of hospitalization using this approach.

Effect of atorvastatin on paraoxonase1 (PON1) and oxidative status.

It has been proposed that paraoxonase1 (PON1), a high density lipoprotein (HDL)-associated esterase/lactonase, has anti-atherosclerotic properties. The activity of PON1 is influenced by PON1 polymorphisms. However, the influence of PON1 polymorphisms on PON1 activity and oxidative stress in response to lipid-lowering drugs remains poorly understood. The objective of the present study was to investigate the effects of atorvastatin on PON1 activity and oxidative status. The influence of PON1 polymorphisms on PON1 activity and oxidative status in response to atorvastatin treatment was also evaluated. In total, 22 hypercholesterolemic patients were treated with atorvastatin at a dose of 10 mg/day for 3 months. Lipid profile, lipid oxidation markers (malondialdehyde (MDA), conjugated diene (CD), total peroxides (TP)), total antioxidant substance (TAS), oxidative stress index (OSI), and paraoxonase1 activity were determined before and after treatment. L55M, Q192R, and T(-107)C PON1 polymorphisms were also determined. Atorvastatin treatment significantly reduced the levels of total cholesterol (24.5%), low density lipoprotein (LDL) cholesterol (25.4%), triglycerides (24.4%), CD (4.4%), MDA (15.2%), TP (13.0%) and OSI (24.0%), and significantly increased the levels of TAS (27.3%), and PON1 activity (14.0%). Interestingly, the increase in PON1 activity and the reduction in oxidative stress in response to atorvastatin were influenced only by the PON1 T-107C polymorphism. Atorvastatin treatment improved the lipid profile, lipid oxidation, and oxidative/antioxidative status markers including the activity of PON1 towards paraoxon. These beneficial effects may be attributed to the antioxidant properties of statins and the increase in PON1 activity. The increase in PON1 activity was enhanced by the PON1 T-107C polymorphism.