Serious adverse drug events associated with psychotropic treatment of bipolar or schizoaffective disorder: a 17-year follow-up on the LiSIE retrospective cohort study

Introduction

Mood stabilisers and other psychotropic drugs can lead to serious adverse drug events (ADEs). However, the incidence remains unknown. We aimed to (a) determine the incidence of serious ADEs in patients with bipolar or schizoaffective disorders, (b) explore the role of lithium exposure, and (c) describe the aetiology.

Methods

This study is part of the LiSIE (Lithium-Study into Effects and Side Effects) retrospective cohort study. Between 2001 and 2017, patients in the Swedish region of Norrbotten, with a diagnosis of bipolar or schizoaffective disorder, were screened for serious ADEs to psychotropic drugs, having resulted in critical, post-anaesthesia, or intensive care. We determined the incidence rate of serious ADEs/1,000 person-years (PY).

Results

In 1,521 patients, we identified 41 serious ADEs, yielding an incidence rate of 1.9 events per 1,000 PY. The incidence rate ratio (IRR) between ADEs with lithium present and causally implicated and ADEs without lithium exposure was significant at 2.59 (95% CI 1.20-5.51; p = 0.0094). The IRR of ADEs in patients <65 and ≥65 years was significant at 3.36 (95% CI 1.63-6.63; p = 0.0007). The most common ADEs were chronic lithium intoxication, oversedation, and cardiac/blood pressure-related events.

Discussion

Serious ADEs related to treatment of bipolar (BD) or schizoaffective disorder (SZD) were uncommon but not rare. Older individuals were particularly at risk. The risk was higher in individuals exposed to lithium. Serum lithium concentration should always be checked when patients present with new or unclear somatic symptoms. However, severe ADEs also occurred with other mood stabilisers and other psychotropic drugs.

Estimating the clinical and budgetary impact of using angiotensin receptor neprilysin inhibitor as first line therapy in patients with HFrEF

AIMS

Recent updates of international treatment guidelines for heart failure with reduced ejection fraction (HFrEF) differ regarding the use of angiotensin receptor neprilysin inhibitor (ARNI) as first-line treatment. The American Heart Association/American College of Cardiology/Heart Failure Society of America (AHA/ACC/HFSA) 2022 guidelines gives ARNI a Class IA recommendation for HFrEF patients while the European Society of Cardiology's guidelines are less clear when ARNI could be considered as first line treatment option in de novo patients. This study aimed to model the clinical and budgetary outcomes of implementing these guidelines, comparing conservative ARNI prescription patterns with less conservative in Sweden and in the United Kingdom.

METHODS AND RESULTS

A health economic model was developed to compare different treatment patterns for HFrEF. Incident cohorts were included on an annual basis and followed over 10 years. The model included treatment specific all-cause mortality and hospitalization rates, as well as drug acquisition, monitoring, and hospitalization costs. Increasing the use of ARNI could lead to about 7000-12 300 life years gained and 2600-4600 hospitalizations prevented in Sweden. These health benefits come with an additional cost of 112-195 million euros. Similar results were estimated for the United Kingdom, albeit on a larger population.

CONCLUSIONS

Increasing the proportion of patients receiving ARNI instead of angiotensin converting enzyme inhibitors as first-line treatment of HFrEF will lead to a considerable number of additional life years gained and prevented hospitalizations but with additional cost in terms of health care expenditure in Sweden and in the United Kingdom.

Low carbohydrate high fat-diet in real life assessed by diet history interviews

BACKGROUND

Low carbohydrate high fat (LCHF) diet has been a popular low carbohydrate diet in Sweden for 15 years. Many people choose LCHF to lose weight or control diabetes, but there are concerns about the effect on long-term cardiovascular risks. There is little data on how a LCHF diet is composed in real-life. The aim of this study was to evaluate the dietary intake in a population with self-reported adherence to a LCHF diet.

METHODS

A cross-sectional study of 100 volunteers that considered themselves eating LCHF was conducted. Diet history interviews (DHIs) and physical activity monitoring for validation of the DHIs were performed.

RESULTS

The validation shows acceptable agreement of measured energy expenditure and reported energy intake. Median carbohydrate intake was 8.7 E% and 63% reported carbohydrate intake at potentially ketogenic levels. Median protein intake was 16.9 E%. The main source of energy was dietary fats (72.0 E%). Intake of saturated fat was 32 E% and cholesterol was 700 mg per day, both of which exceeded the recommended upper limits according to nutritional guidelines. Intake of dietary fiber was very low in our population. The use of dietary supplements was high, and it was more common to exceed the recommended upper limits of micronutrients than to have an intake below the lower limits.

CONCLUSIONS

Our study indicates that in a well-motivated population, a diet with very low carbohydrate intake can be sustained over time and without apparent risk of deficiencies. High intake of saturated fats and cholesterol as well as low intake of dietary fiber remains a concern.

Prevalence and prognostic impact of left ventricular systolic dysfunction or pulmonary congestion after acute myocardial infarction

AIMS

The aim was to describe the prevalence, characteristics, and outcome of patients with acute myocardial infarction (MI) developing left ventricular (LV) systolic dysfunction or pulmonary congestion by applying different criteria to define the population.

METHODS AND RESULTS

In patients with MI included in the Swedish web-system for enhancement and development of evidence-based care in heart disease (SWEDEHEART) registry, four different sets of criteria were applied, creating four not mutually exclusive subsets of patients: patients with MI and ejection fraction (EF) < 50% and/or pulmonary congestion (subset 1); EF < 40% and/or pulmonary congestion (subset 2); EF < 40% and/or pulmonary congestion and at least one high-risk feature (subset 3, PARADISE-MI like); and EF < 50% and no diabetes mellitus (subset 4, DAPA-MI like). Subsets 1, 2, 3, and 4 constituted 31.6%, 15.0%, 12.8%, and 22.8% of all patients with MI (n = 87 177), respectively. The age and prevalence of different co-morbidities varied between subsets. For median age, 70 to 77, for diabetes mellitus, 22 to 33%; for chronic kidney disease, 22 to 38%, for prior MI, 17 to 21%, for atrial fibrillation, 7 to 14%, and for ST-elevations, 38 to 50%. The cumulative incidence of death or heart failure hospitalization at 3 years was 17.4% (95% CI: 17.1-17.7%) in all MIs; 26.9% (26.3-27.4%) in subset 1; 37.6% (36.7-38.5%) in subset 2; 41.8% (40.7-42.8%) in subset 3; and 22.6% (22.0-23.2%) in subset 4.

CONCLUSIONS

Depending on the definition, LV systolic dysfunction or pulmonary congestion is present in 13-32% of all patients with MI and is associated with a two to three times higher risk of subsequent death or HF admission. There is a need to optimize management and improve outcomes for this high-risk population.

Prevalence and treatment of diabetes and pre-diabetes in a real-world heart failure population: a single-centre cross-sectional study

AIMS

The aim of this study was to investigate a real-world heart failure (HF) cohort regarding (1) prevalence of known diabetes mellitus (DM), undiagnosed DM and pre-diabetes, (2) if hf treatment differs depending on glycaemic status and (3) if treatment of DM differs depending on HF phenotype.

METHODS

All patients who had received a diagnosis of HF at Umeå University Hospital between 2010 and 2019 were identified and data were extracted from patient files according to a prespecified protocol containing parameters for clinical characteristics, including echocardiogram results, comorbidities, fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) values. Patients' HF phenotype was determined using the latest available echocardiogram. The number of patients with previous DM diagnosis was assessed. Patients without a previous diagnosis of DM were classified as non-DM, pre-diabetes or probable DM according to FPG and HbA1c levels using WHO criteria.

RESULTS

In total, 2326 patients (59% male, mean age 76±13 years) with HF and at least one echocardiogram were assessed. Of these, 617 (27%) patients had a previous diagnosis of DM. Of the 1709 patients without a previous diagnosis of DM, 1092 (67%) patients had either an FPG or HbA1c recorded, of which 441 (41%) met criteria for pre-diabetes and 97 (9%) met criteria for probable diabetes, corresponding to 19% and 4% of the entire cohort, respectively. Patients with HF and diabetes were more often treated with diuretics and beta blockers compared with non-DM patients (64% vs 42%, p<0.001 and 88% vs 83%, p<0.001, respectively). There was no difference in DM treatment between HF phenotypes.

CONCLUSIONS

DM and pre-diabetes are common in this HF population with 50% of patients having either known DM, probable DM or pre-diabetes. Patients with HF and DM are more often treated with common HF medications. HF phenotype did not affect choice of DM therapy.

Characteristics and management of very elderly patients with heart failure: a retrospective, population cohort study

AIMS

Unmet needs exist in the diagnosis and treatment of heart failure (HF) in the elderly population. Our aim was to analyse and compare data of diagnostics and management of very elderly patients (aged ≥85 years) compared with younger patients (aged 18-84 years) with HF in Sweden.

METHODS

Incidence of ≥2 HF diagnosis (ICD-10) was identified from primary/secondary care in Uppsala and Västerbotten during 2010-2015 via electronic medical records linked to data from national health registers. Analyses investigated the diagnosis, treatment patterns, hospitalizations and outpatient visits, and mortality.

RESULTS

Of 8702 patients, 27.7% were ≥85 years old, women (60.2%); most patients (80.7%) had unknown left ventricular ejection fraction; key co-morbidities comprised anaemia, dementia, and cerebrovascular disease. More very elderly patients received cardiovascular disease (CVD)-related management after diagnosis in primary care (13.6% vs. 6.5%; P < 0.0001), but fewer patients underwent echocardiography (19.3% vs. 42.9%; P < 0.0001). Within 1 year of diagnosis, very elderly patients were less likely to be hospitalized (all-cause admissions per patient: 1.9 vs. 2.3; P < 0.0001; CVD-related admissions per patient: 1.8 vs. 2.1; P = 0.0004) or prescribed an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB) plus a β-blocker (45.2% vs. 56.9%; P < 0.0001) or an ACEI/ARB plus a β-blocker plus a mineralocorticoid receptor antagonist (15.4% vs. 31.7%; P < 0.0001). One-year mortality was high in patients ≥85 years old, 30.5% (CI: 28.3-32.7%) out of 1797 patients.

CONCLUSIONS

Despite the large number of very elderly patients with newly diagnosed HF in Sweden, poor diagnostic work-up and subsequent treatment highlight the inequality of care in this vulnerable population.

Motives, frequency, predictors and outcomes of MRA discontinuation in a real-world heart failure population

INTRODUCTION

Mineralocorticoid receptor antagonists (MRAs) reduce mortality and morbidity in patients with heart failure and reduced ejection fraction (HFrEF), but are largely underused. We evaluated the frequency, motives, predictors and outcomes of MRA discontinuation in a real-world heart failure population.

METHODS AND RESULTS

This was a single-centre, retrospective cohort study where medical record-based data were collected on patients with HFrEF between 2010 and 2018. In the final analysis, 572 patients were included that comprised the continued MRA group (n=275) and the discontinued MRA group (n=297). Patients that discontinued MRA were older, had a higher comorbidity index and a lower index estimated glomerular filtration rate (eGFR). Predictors of MRA discontinuations were increased S-potassium, lower eGFR, lower systolic blood pressure, higher frequency of comorbidities and a higher left ventricular ejection fraction. The most common reason for MRA discontinuation was renal dysfunction (n=97, 33%) with 59% of these having an eGFR <30 mL/min/1.73m², and elevated S-potassium (n=71, 24%) with 32% of these having an S-potassium >5.5 mmol/L. Discontinuation of MRA increased the adjusted risk of all-cause mortality (HR 1.48; 95% CI 1.07 to 2.05; p=0.019).

CONCLUSIONS

Half of all patients with HFrEF initiated on MRA discontinued the treatment. A substantial number of patients discontinued MRA without meeting the guideline-recommended levels of eGFR and S-potassium where mild to moderate hyperkalaemia seems to be the most decisive predictor. Further, MRA discontinuation was associated with increased adjusted risk of all-cause mortality.

Risks of deep vein thrombosis, pulmonary embolism, and bleeding after covid-19: nationwide self-controlled cases series and matched cohort study

OBJECTIVE

To quantify the risk of deep vein thrombosis, pulmonary embolism, and bleeding after covid-19.

DESIGN

Self-controlled case series and matched cohort study.

SETTING

National registries in Sweden.

PARTICIPANTS

1 057 174 people who tested positive for SARS-CoV-2 between 1 February 2020 and 25 May 2021 in Sweden, matched on age, sex, and county of residence to 4 076 342 control participants.

MAIN OUTCOMES MEASURES

Self-controlled case series and conditional Poisson regression were used to determine the incidence rate ratio and risk ratio with corresponding 95% confidence intervals for a first deep vein thrombosis, pulmonary embolism, or bleeding event. In the self-controlled case series, the incidence rate ratios for first time outcomes after covid-19 were determined using set time intervals and the spline model. The risk ratios for first time and all events were determined during days 1-30 after covid-19 or index date using the matched cohort study, and adjusting for potential confounders (comorbidities, cancer, surgery, long term anticoagulation treatment, previous venous thromboembolism, or previous bleeding event).

RESULTS

Compared with the control period, incidence rate ratios were significantly increased 70 days after covid-19 for deep vein thrombosis, 110 days for pulmonary embolism, and 60 days for bleeding. In particular, incidence rate ratios for a first pulmonary embolism were 36.17 (95% confidence interval 31.55 to 41.47) during the first week after covid-19 and 46.40 (40.61 to 53.02) during the second week. Incidence rate ratios during days 1-30 after covid-19 were 5.90 (5.12 to 6.80) for deep vein thrombosis, 31.59 (27.99 to 35.63) for pulmonary embolism, and 2.48 (2.30 to 2.68) for bleeding. Similarly, the risk ratios during days 1-30 after covid-19 were 4.98 (4.96 to 5.01) for deep vein thrombosis, 33.05 (32.8 to 33.3) for pulmonary embolism, and 1.88 (1.71 to 2.07) for bleeding, after adjusting for the effect of potential confounders. The rate ratios were highest in patients with critical covid-19 and highest during the first pandemic wave in Sweden compared with the second and third waves. In the same period, the absolute risk among patients with covid-19 was 0.039% (401 events) for deep vein thrombosis, 0.17% (1761 events) for pulmonary embolism, and 0.101% (1002 events) for bleeding.

CONCLUSIONS

The findings of this study suggest that covid-19 is a risk factor for deep vein thrombosis, pulmonary embolism, and bleeding. These results could impact recommendations on diagnostic and prophylactic strategies against venous thromboembolism after covid-19.

Avoiding bias in self-controlled case series studies of coronavirus disease 2019

Many studies, including self-controlled case series (SCCS) studies, are being undertaken to quantify the risks of complications following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19). One such SCCS study, based on all COVID-19 cases arising in Sweden over an 8-month period, has shown that SARS-CoV-2 infection increases the risks of AMI and ischemic stroke. Some features of SARS-CoV-2 infection and COVID-19, present in this study and likely in others, complicate the analysis and may introduce bias. In the present paper we describe these features, and explore the biases they may generate. Motivated by data-based simulations, we propose methods to reduce or remove these biases.

Healthcare resource utilisation and costs associated with a heart failure diagnosis: a retrospective, population-based cohort study in Sweden

OBJECTIVES

To examine healthcare resource use (HRU) and costs among heart failure (HF) patients using population data from Sweden.

DESIGN

Retrospective, non-interventional cohort study.

SETTING

Two cohorts were identified from linked national health registers (cohort 1, 2005-2014) and electronic medical records (cohort 2, 2010-2012; primary/secondary care patients from Uppsala and Västerbotten).

PARTICIPANTS

Patients (aged ≥18 years) with primary or secondary diagnoses of HF (≥2 International Classification of Diseases and Related Health Problems, 10th revision classification) during the identification period of January 2005 to March 2015 were included.

OUTCOME MEASURES

HRU across the HF phenotypes was assessed with logistic regression. Costs were estimated based on diagnosis-related group codes and general price lists.

RESULTS

Total annual costs of secondary care of prevalent HF increased from SEK 6.23 (€0.60) to 8.86 (€0.85) billion between 2005 and 2014. Of 4648 incident patients, HF phenotype was known for 1715: reduced ejection fraction (HFrEF): 64.5%, preserved ejection fraction (HFpEF): 35.5%. Within 1 year of HF diagnosis, the proportion of patients hospitalised was only marginally higher for HFrEF versus HFpEF (all-cause (95% CI): 64.7% (60.8 to 68.4) vs 63.7% (60.8 to 66.5), HR 0.91, p=0.14; cardiovascular disease related (95% CI): 61.1% (57.1 to 64.8) vs 60.9% (58.0 to 63.7), HR 0.93, p=0.28). Frequency of hospitalisations and outpatient visits per patient declined after the first year. All-cause secondary care costs in the first year were SEK 122 758 (€12 890)/patient/year, with HF-specific care accounting for 69% of the costs. Overall, 10% of the most expensive population (younger; predominantly male; more likely to have comorbidities) incurred ~40% of total secondary care costs.

CONCLUSIONS

HF-associated costs and HRU are high, especially during the first year of diagnosis. This is driven by high hospitalisations rates. Understanding the profile of resource-intensive patients being at younger age, male sex and high Charlson comorbidity index scores at the time of the HF diagnosis is most likely a sign of more severe disease.

Risk of acute myocardial infarction and ischaemic stroke following COVID-19 in Sweden: a self-controlled case series and matched cohort study

BACKGROUND

COVID-19 is a complex disease targeting many organs. Previous studies highlight COVID-19 as a probable risk factor for acute cardiovascular complications. We aimed to quantify the risk of acute myocardial infarction and ischaemic stroke associated with COVID-19 by analysing all COVID-19 cases in Sweden.

METHODS

This self-controlled case series (SCCS) and matched cohort study was done in Sweden. The personal identification numbers of all patients with COVID-19 in Sweden from Feb 1 to Sept 14, 2020, were identified and cross-linked with national inpatient, outpatient, cancer, and cause of death registers. The controls were matched on age, sex, and county of residence in Sweden. International Classification of Diseases codes for acute myocardial infarction or ischaemic stroke were identified in causes of hospital admission for all patients with COVID-19 in the SCCS and all patients with COVID-19 and the matched control individuals in the matched cohort study. The SCCS method was used to calculate the incidence rate ratio (IRR) for first acute myocardial infarction or ischaemic stroke following COVID-19 compared with a control period. The matched cohort study was used to determine the increased risk that COVID-19 confers compared with the background population of increased acute myocardial infarction or ischaemic stroke in the first 2 weeks following COVID-19.

FINDINGS

86 742 patients with COVID-19 were included in the SCCS study, and 348 481 matched control individuals were also included in the matched cohort study. When day of exposure was excluded from the risk period in the SCCS, the IRR for acute myocardial infarction was 2·89 (95% CI 1·51-5·55) for the first week, 2·53 (1·29-4·94) for the second week, and 1·60 (0·84-3·04) in weeks 3 and 4 following COVID-19. When day of exposure was included in the risk period, IRR was 8·44 (5·45-13·08) for the first week, 2·56 (1·31-5·01) for the second week, and 1·62 (0·85-3·09) for weeks 3 and 4 following COVID-19. The corresponding IRRs for ischaemic stroke when day of exposure was excluded from the risk period were 2·97 (1·71-5·15) in the first week, 2·80 (1·60-4·88) in the second week, and 2·10 (1·33-3·32) in weeks 3 and 4 following COVID-19; when day of exposure was included in the risk period, the IRRs were 6·18 (4·06-9·42) for the first week, 2·85 (1·64-4·97) for the second week, and 2·14 (1·36-3·38) for weeks 3 and 4 following COVID-19. In the matched cohort analysis excluding day 0, the odds ratio (OR) for acute myocardial infarction was 3·41 (1·58-7·36) and for stroke was 3·63 (1·69-7·80) in the 2 weeks following COVID-19. When day 0 was included in the matched cohort study, the OR for acute myocardial infarction was 6·61 (3·56-12·20) and for ischaemic stroke was 6·74 (3·71-12·20) in the 2 weeks following COVID-19.

INTERPRETATION

Our findings suggest that COVID-19 is a risk factor for acute myocardial infarction and ischaemic stroke. This indicates that acute myocardial infarction and ischaemic stroke represent a part of the clinical picture of COVID-19, and highlights the need for vaccination against COVID-19.

FUNDING

Central ALF-funding and Base Unit ALF-Funding, Region Västerbotten, Sweden; Strategic funding during 2020 from the Department of Clinical Microbiology, Umeå University, Sweden; Stroke Research in Northern Sweden; The Laboratory for Molecular Infection Medicine Sweden.

Combining ECG and echocardiography to identify transthyretin cardiac amyloidosis in heart failure

AIMS/BACKGROUND

Transthyretin amyloid (ATTR) amyloidosis cardiomyopathy is an underdiagnosed, causatively treatable cause of heart failure (HF). The aim of this study was to evaluate the efficacy of electrocardiogram (ECG) and echocardiography on patients with increased interventricular septum diameter (IVSd) to identify ATTR cardiac amyloidosis (ATTR-CA) patients.

METHODS

We investigated 58 patients with HF and an IVSd > 14 mm. Included were 33 ATTR-CA patients and 25 controls that consisted of non-amyloidosis HFpatients with negative 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scintigraphy. We used echocardiography including 2D speckle-tracking strain and a 12-lead ECG to test the accuracy to differentiate the groups.

RESULTS

We found high diagnostic accuracy (98%) for differentiating ATTR-CA from HF controls using a combination of R amplitude in -aVR from ECG and relative wall thickness acquired from echocardiography. With this combined model (RWT/R in -aVR), the sensitivity was 100% and specificity was 95% using a cut-off value of 0.90. Furthermore, the area under the curve was 99% and the negative predictive value was 100%.

CONCLUSION

We found that a simple combination of ECG and echocardiographic parameters used in clinical settings was able to differentiate ATTR-CA from other aetiologies of HF with increased interventricular septum thickness. The high sensitivity and negative predictive value render the algorithm useful for selection of patients for further diagnostic procedures for ATTR-CA.

Monoaminoxidase inhibitors as a cause of serotonin syndrome – a systematic case review based on meta-analytic principles

Introduction

Serotonin syndrome (SS) is a toxic state characterized by increased serotonin activity. It has been suggested that severe serotonin syndrome usually involves monoaminoxidase inhibitors (MAOIs).

Objectives

To quantify in how far severe SS is associated with MAOIs.

Methods

Systematic review and quantitative analysis of all SS cases published between 1 January 2004 and 31 December 2014. Severe SS was defined as cases, either requiring intensive care or resulting in death. Cases were included if they met the diagnostic criteria for SS according to at least one of the three diagnostic criteria systems (Hunter, Radomski and Sternbach).

Results

Of the 299 included cases, 118 (39%) met the definition for severe SS. Eight cases had insufficient information to enable severity classification. Of the severe cases, 48 (40%) involved a MAOI. Of these, 67% related to psychiatric MAOIs, such as phenelzine and moclobemide and 33% to a somatic MAOI, such as methylene blue and linezolid. Of the remaining 173 non-severe SS cases, 24 cases (13%) involved a MAOI. In these, 12% related to a psychiatric MAOI and 83% to a somatic MAOI. One case (4%) had a combination of both. The odds ratio for MAOI involvement in severe versus non-severe serotonin syndrome was 4.3 (CI 2.4 – 7.5; p < 0.001).

Conclusions

In the majority of published case reports, drugs other than MAOIs are involved in serotonin syndrome, even in severe cases. MAOIs are, however, more common in severe serotonin syndrome than in non-severe cases.

Conflict of interest

M. Ott: scientific advisory board member of Astra Zeneca, Sweden. U. Werneke: received funding for educational activities on behalf of Norrbotten Region; Astra Zeneca, Eli Lilly, Janssen, Novartis, Otsuka/Lundbeck, Servier, Shire, Sunovion. Others: None

ECG changes associated with lithium intoxication – a study based on the lisie project

Introduction

It currently remains unclear in how far supratherapeutic lithium serum concentrations can affect the cardiac conduction system. Prolonged QT interval, arrhythmias and cardiac death have all been anecdotally reported, but the systematic studies are few.

Objectives

To examine ECG changes occurring with supratherapeutic lithium concentrations that have given rise to lithium toxicity.

Methods

We examined all episodes of lithium intoxication defined as serum lithium level (≥ 1.5 mmol/L). We analyzed ECG before, during and after intoxication and recorded ECG changes. These, we then assessed according to type of intoxications, clinical and other pharmacological characteristics. The study is based on 20-year data (1997-2020) from the retrospective cohort study (LiSIE) in the Swedish region of Norrbotten.

Results

Of 1101 patients treated with lithium, 77 patients had experienced lithium intoxications. 12 patients had more than one episode of intoxication, yielding 91 episodes. 39 had ECG available both as reference and during lithium intoxication. We found no statistically significant prolongation of the QTc interval during lithium intoxication, compared to respective reference ECG (p = 0.364). Heart rate during lithium intoxication was significantly lower, mean 73 beats/min (SD 16,8, range 43 - 112), compared to the reference ECG, mean 79 beats/min (SD 15,3, range 48-112; p = 0.006). No patient died. All findings were independent of whether an intoxication was acute or chronic.

Conclusions

In our study, heart rate was significantly lower during episodes of intoxication. However, this decrease was of no clinical relevance in most cases. Lithium intoxication was not associated with prolonged QT time.

Disclosure

M. Ott: scientific advisory board member of Astra Zeneca, Sweden. U. Werneke: received funding for educational activities on behalf of Norrbotten Region; Astra Zeneca, Eli Lilly, Janssen, Novartis, Otsuka/Lundbeck, Servier, Shire, Sunovion. Others: None

Recurrent heart failure hospitalizations increase the risk of cardiovascular and all-cause mortality in patients with heart failure in Sweden: a real-world study

Aims

Heart failure (HF) is a leading cause of hospitalization and is associated with high morbidity and mortality. We examined the impact of recurrent HF hospitalizations (HFHs) on cardiovascular (CV) mortality among patients with HF in Sweden.

Methods and results

Adults with incident HF were identified from linked national health registers and electronic medical records from 01 January 2005 to 31 December 2013 for Uppsala and until 31 December 2014 for Västerbotten. CV mortality and all‐cause mortality were evaluated. A time‐dependent Cox regression model was used to estimate relative CV mortality rates for recurrent HFHs. Assessment was also done for ejection fraction‐based HF phenotypes and for comorbid atrial fibrillation, diabetes, or chronic renal impairment. Overall, 3878 patients with HF having an index hospitalization were included, providing 9691.9 patient‐years of follow‐up. Patients were relatively old (median age: 80 years) and were more frequently male (55.5%). Compared with patients without recurrent HFHs, the adjusted hazard ratio (HR [95% confidence interval; CI]) for CV mortality and all‐cause mortality were statistically significant for patients with one, two, three, and four or more recurrent HFHs. The risk of CV mortality and all‐cause mortality increased approximately six‐fold in patients with four or more recurrent HFHs vs. those without any HFHs (HR [95% CI]: 6.26 [5.24–7.48] and 5.59 [4.70–6.64], respectively). Similar patterns were observed across the HF phenotypes and patients with comorbidities.

Conclusions

There is a strong association between recurrent HFHs and CV and all‐cause mortality, with the risk increasing progressively with each recurrent HFH.

Prevalence of wild type transtyrethin cardiac amyloidosis in a heart failure clinic

Aims

Wild type transthyretin amyloidosis (ATTRwt) has gained interest during recent years due to better diagnostic tools and the emergence of treatment options. Little is known about the prevalence of the disease. We aimed to investigate the prevalence in a heart failure population with myocardial hypertrophy.

Methods and results

All patients with an ICD code of heart failure living within the catchment area of Umeå University hospital and intraventricular septum >14 mm were offered screening with 3,3‐diphosphono‐1,2‐propanodicarboxylic acid (DPD) scan and a clinical work up. Out of 2238 patients with heart failure, 174 patients were found to have a septum >14 mm. Ten patients were already diagnosed with hereditary ATTR cardiomyopathy, 12 patients had ATTRwt cardiomyopathy, 12 patients had known HCM, one patient had AL amyloidosis, and four patients had already undergone a negative DPD scan (DPD uptake grade 0 and 1) within the last 3 years. This left 134 patients who we tried to contact for screening, but 48 patients had either died or declined to participate. Out of 86 screened patients, 13 had a DPD uptake of grade 2 or 3 without other amyloid disease making the total number of patients with ATTRwt in this population 25.

Conclusions

Approximately 20% of investigated patients in a cohort with heart failure and increased myocardial wall thickness has ATTRwt. Calculated for the whole population of heart failure patients, the prevalence is just over 1.1%. Comparing this number to the total population would give an estimated prevalence of 1:6000.

Implementation of sacubitril/valsartan in Sweden: clinical characteristics, titration patterns, and determinants

Aims

The aim of this study is to study the introduction of sacubitril/valsartan (sac/val) in Sweden with regards to regional differences, clinical characteristics, titration patterns, and determinants of use and discontinuation.

Methods and results

A national cohort of heart failure was defined from the Swedish Prescribed Drug Register and National Patient Register. A subcohort with additional data from the Swedish Heart Failure Registry (SwedeHF) was also studied. Cohorts were subdivided as per sac/val prescription and registration in SwedeHF. Median sac/val prescription rate was 20 per 100 000 inhabitants. Between April 2016 and December 2017, we identified 2037 patients with ≥1 sac/val prescription, of which 1144 (56%) were registered in SwedeHF. Overall, patients prescribed with sac/val were younger, more frequently male, and had less prior cardiovascular disease than non‐sac/val patients. In SwedeHF subcohort, patients prescribed with sac/val had lower ejection fraction. Overall, younger age [hazard ratio 2.81 (95% confidence interval 2.45–3.22)], registration in SwedeHF [1.97 (1.83–2.12)], male gender [1.50 (1.37–1.64)], ischaemic heart disease [1.50 (1.39–1.62)], lower left ventricular ejection fraction [3.06 (2.18–4.31)], and New York Heart Association IV [1.50 (1.22–1.84)] were predictors for sac/val use. As initiation dose in the sac/val cohort, 38% received 24/26 mg, 54% 49/51 mg, and 9% 97/103 mg. Up‐titration to the target dose was achieved in 57% of the overall cohort over a median follow‐up of 6 months. The estimated treatment persistence for any dose at 360 days was 82%.

Conclusions

Implementation of sac/val in Sweden was slow and varied five‐fold across different regions; younger age, male, SwedeHF registration, and ischaemic heart disease were among the independent predictors of receiving sac/val. Overall, treatment persistence and tolerability was high.

A systematic approach for introduction of novel treatments to a chronic patient group: sacubitril-valsartan as a case study

Purpose

To develop a model for systematic introduction and to test the feasibility in a chronic disease population. We also investigated how the approach was received by the patients.

Methods and results

The systematic introduction approach is a seven-step procedure: step 1, define a few main criteria; step 2, primary scan patients with the one or two main criteria using computerized medical records/databases/clinical registries; step 3, identify patients applying the other predefined criteria; step 4, evaluate if any examinations/laboratory test updates are required; step 5, summon identified patients to the clinic with an information letter; step 6, discuss treatment with the patient and prescribe if appropriate; and step 7, follow up on initiated therapy and evaluate the applied process. The model was tested in a case study during introduction of the new drug sacubitril-valsartan in a heart failure population. In total, 76 out of 1924 patients were identified to be eligible for sacubitril-valsartan and summoned to the clinic to discuss treatment. Patient experiences with the approach were investigated in an interview study with general inductive approach using qualitative content analysis. This resulted in three final categories: a good approach, role of the information letter, and trust in care.

Conclusions

The systematic introduction approach ensures that strict criteria are used in the selection process and that a treatment can be implemented in eligible patients within a specified population with limited resources and time. The model was effective in our case study and maintained the patient’s confidence in healthcare.

Comparison of creatinine-based methods for estimating glomerular filtration rate in patients with heart failure

AIMS

Glomerular filtration rate is an important factor in management of heart failure (HF). Our objective was to validate eight creatinine-based equations for estimating glomerular filtration rate (eGFR) in an HF population against measured glomerular filtration rate.

METHODS AND RESULTS

One hundred forty-six HF patients (mean age 68 ± 13 years, mean left ventricular ejection fraction 45% ± 15) within a single-centre hospital that underwent 51 Cr-EDTA clearance between 2010 and 2018 were included in this retrospective study. eGFR was estimated by means of Cockcroft-Gault ideal and actual weight, the Modification of Diet in Renal Disease Study (MDRD), simplified MDRD with isotope dilution mass spectroscopy traceable calibration, the Chronic Kidney Disease Epidemiology Collaboration, revised Lund-Malmö, full age spectrum, and the Berlin Initiative Study 1. Mean measured glomerular filtration rate was 42 mL/min/1.73 m2 . Pearson's correlation coefficient (r) had the highest precision for MDRD (r = 0.9), followed by revised Lund-Malmö (r = 0.88). All equations except MDRD (mean difference -4.8%) resulted in an overestimation of the renal function. The accuracy was below 75% for all equations except MDRD.

CONCLUSIONS

None of the exclusively creatinine-based methods was accurate in predicting eGFR in HF patients. Our findings suggest that more accurate methods are needed for determining eGFR in patients with HF.

Randomized trial of a left ventricular assist device as destination therapy versus guideline-directed medical therapy in patients with advanced heart failure. Rationale and design of the SWEdish evaluation of left Ventricular Assist Device (SweVAD) trial

AIMS

Patients with advanced heart failure (AdHF) who are ineligible for heart transplantation (HTx) can become candidates for treatment with a left ventricular assist device (LVAD) in some countries, but not others. This reflects the lack of a systematic analysis of the usefulness of LVAD systems in this context, and of their benefits, limitations and cost-effectiveness. The SWEdish evaluation of left Ventricular Assist Device (SweVAD) study is a Phase IV, prospective, 1:1 randomized, non-blinded, multicentre trial that will examine the impact of assignment to mechanical circulatory support with guideline-directed LVAD destination therapy (GD-LVAD-DT) using the HeartMate 3 (HM3) continuous flow pump vs. guideline-directed medical therapy (GDMT) on survival in a population of AdHF patients ineligible for HTx.

METHODS

A total of 80 patients will be recruited to SweVAD at the seven university hospitals in Sweden. The study population will comprise patients with AdHF (New York Heart Association class IIIB-IV, INTERMACS profile 2-6) who display signs of poor prognosis despite GDMT and who are not considered eligible for HTx. Participants will be followed for 2 years or until death occurs. Other endpoints will be determined by blinded adjudication. Patients who remain on study-assigned interventions beyond 2 years will be asked to continue follow-up for outcomes and adverse events for up to 5 years.

CONCLUSION

The SweVAD study will compare survival, medium-term benefits, costs and potential hazards between GD-LVAD-DT and GDMT and will provide a valuable reference point to guide destination therapy strategies for patients with AdHF ineligible for HTx.

Health-related quality of life in patients with heart failure eligible for treatment with sacubitril-valsartan

Aim

To describe and compare self‐reported health‐related quality of life between younger and older patients with severe heart failure eligible for treatment with sacubitril–valsartan and to explore the association between health‐related quality of life and age, NYHA classification, systolic blood pressure and NT‐proBNP level.

Design

Cross‐sectional study.

Methods

A total of 59 patients, eligible for treatment with sacubitril–valsartan were consecutively included and divided into a younger (≤75 years) and older group (>75 years). Health‐related quality of life was assessed using the Kansas City Cardiomyopathy Questionnaire and the EuroQol 5‐dimensions. Data were collected between June 2016 and January 2018. The STROBE checklist was used.

Results

There were no differences in overall health‐related quality of life between the age groups. The older patients reported lower scores in two domains measured with the Kansas City Cardiomyopathy Questionnaire, namely self‐efficacy (67.0 SD 22.1 vs. 78.8 SD 19.7) and physical limitation (75.6 SD 19.0 vs. 86.3 SD 14.4). Higher NYHA class was independently associated with lower Kansas City Cardiomyopathy Questionnaire Overall Summary Score.

P335Prevalence of transthyretin cardiac amyloidosis in a community-based heart failure population

Introduction

Cardiac wild type (wt) transthyretin (ATTR) amyloidos causes hypertrophic, restrictive cardiomyopathy in older patients and is generally considered underdiagnosed. However, its prevalence remains poorly investigated. Scintigraphy using bone tracers, e.g. Tc-PYP and Tc-DPD, is a highly sensitive and specific method for detection of cardiac ATTR and has revolutionised diagnostics The aim of this study was to describe the prevalence of wtATTR amyloidosis in our heart failure population.

Methods

Our University Hospital is the sole provider of specialised heart care in an area with around 150 000 inhabitants, 37 600 of which are older than 60 years. Medical records for all living patients in the area with a diagnosis of heart failure, hypertensive heart disease or cardiomyopathy between 2010 and May 2018 were scrutinized (n=2237). 95% of these patients had an echocardiographic exam available for re-evaluation. All patients withseptal thickness >14 mm who had no previous DPD scintigraphy or genetic diagnosis of sarcomeric hypertophic cardiomyopathy were offered DPD scintigraphy (n=131). Eight patients died prior to and 38 patients declined work up, mainly due to old age.

A DPD uptake of grade 2 or higher was considered diagnostic in absence of signs of AL amyloidosis.

Results

Adding up patients found during the screening effort and those with an already known diagnosis of wtATTR amyloidosis, 26 patients had wtATTR. Their men age was 84 years and 90% were male.

Conclusions

The study gives us an estimated prevalence of disease warranting specialized heart failure treatment of 1/1500 in the population older than 60 years. Cardiac wtATTR amyloidosis is common in patients with heart failure and increased LV wall thickness, especially among the older male patients. Therefore we recommend a liberal use of bone scintigraphy in this group.

Safety and Tolerability of Initiating Maximum-Dose Sacubitril-Valsartan in Patients on Target Dose Renin-Angiotensin System Inhibitors

AIM

Sacubitril-valsartan has proven beneficial in heart failure with reduced ejection fraction. Guidelines recommend initiating half-dose sacubitril-valsartan before up-titration even to patients already on target dose angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARB). To reduce the number of titration steps needed in order to simplify for the patient as well as the clinic, we aimed to investigate the safety and tolerability of switching patients on target dose ACE inhibitors or ARBs directly to maximum-dose sacubitril-valsartan.

METHODS

This prospective cohort study was conducted between April 2016 and November 2017. A total of 66 patients with heart failure and reduced ejection fraction already on guideline-recommended target dose ACE inhibitors or ARBs (equivalent to enalapril 10 mg twice daily) were switched to maximum-dose sacubitril-valsartan (200 mg twice daily). The patients were followed for twelve months.

RESULTS

Patients had a mean age of 72 ± 10 years, mean systolic blood pressure of 121 ± 17 mmHg, and 92% were male. At 12-month follow-up, nine patients (14%) had discontinued sacubitril-valsartan, four patients (6%) had a dose reduction, and 17 patients (26%) had developed symptomatic hypotension. No angioedema occurred within the 12-month follow-up and there were no hospitalizations or emergency room visits within the first 14 days.

CONCLUSIONS

Switching directly from target dose ACE inhibitors or ARBs to maximum-dose sacubitril-valsartan was safe and generally well tolerated.

Epidemiology of heart failure and trends in diagnostic work-up: a retrospective, population-based cohort study in Sweden

Purpose

The purpose of this study was to examine the trends in heart failure (HF) epidemiology and diagnostic work-up in Sweden.

Methods

Adults with incident HF (≥2 ICD-10 diagnostic codes) were identified from linked national health registers (cohort 1, 2005-2013) and electronic medical records (cohort 2, 2010-2015; primary/secondary care patients from Uppsala and Västerbotten). Trends in annual HF incidence rate and prevalence, risk of all-cause and cardiovascular disease (CVD)-related 1-year mortality and use of diagnostic tests 6 months before and after first HF diagnosis (cohort 2) were assessed.

Results

Baseline demographic and clinical characteristics were similar for cohort 1 (N=174,537) and 2 (N=8,702), with mean ages of 77.4 and 76.6 years, respectively; almost 30% of patients were aged ≥85 years. From 2010 to 2014, age-adjusted annual incidence rate of HF/1,000 inhabitants decreased (from 3.20 to 2.91, cohort 1; from 4.34 to 3.33, cohort 2), while age-adjusted prevalence increased (from 1.61% to 1.72% and from 2.15% to 2.18%, respectively). Age-adjusted 1-year all-cause and CVD-related mortality was higher in men than in women among patients in cohort 1 (all-cause mortality hazard ratio [HR] men vs women 1.07 [95% CI 1.06-1.09] and CVD-related mortality subdistribution HR for men vs women 1.04 [95% CI 1.02-1.07], respectively). While 83.5% of patients underwent N-terminal pro-B-type natriuretic peptide testing, only 36.4% of patients had an echocardiogram at the time of diagnosis, although this increased overtime. In the national prevalent HF population (patients with a diagnosis in 1997-2004 who survived into the analysis period; N=273,999), death from ischemic heart disease and myocardial infarction declined between 2005 and 2013, while death from HF and atrial fibrillation/flutter increased (P<0.0001 for trends over time).

Conclusion

The annual incidence rate of HF declined over time, while prevalence of HF has increased, suggesting that patients with HF were surviving longer over time. Our study confirms that previously reported epidemiological trends persist and remain to ensure proper diagnostic evaluation and management of patients with HF.

Obstacles to mineralocorticoid receptor antagonists in a community-based heart failure population

AIM

Previous studies and national assessments indicate an undertreatment of mineralocorticoid receptor antagonists (MRA) in heart failure with reduced ejection fraction (HFrEF). This study aimed to investigate why MRA is not used to full extent.

METHODS

A complete community-based heart failure population was studied. Several variables were collected, and medical records were scrutinized to identify reasons for not prescribing MRA.

RESULTS

Of 2029 patients, 812 had EF ≤40%. Five hundred and fifty-three patients (68%) tried MRA at some point but 184 of these (33%) discontinued therapy. There were 259 patients that never tried MRA with 177 with a listed explanation or contraindication. Eighty-two patients, 10% of the total HFrEF population, had no clear contraindications. They were older and had less HF hospitalizations compared to patients on MRA (P < 0.05) and 32% did not have any follow-up at the cardiology clinic. Contraindications to MRA were renal dysfunction (93 patients), hypotension (28 patients), and hyperkalemia (25 patients). Only six patients had hyperkalemia without renal dysfunction. Of the patients with renal dysfunction, 66 (72%) had eGFR >30 mL/min.

CONCLUSIONS

The reasons why MRA are underutilized were mainly because of contraindications. However, the data suggest that physicians are overly cautious about moderately reduced kidney function. There seems to be a 10%-18% avoidable undertreatment with MRA, especially for elderly patients that are admitted to the hospital for other reasons than heart failure. This suggests that patients with heart failure would benefit from routine follow-up at a cardiology clinic.

Eligibility of sacubitril-valsartan in a real-world heart failure population: a community-based single-centre study

AIMS

This study aims to investigate the eligibility of the Prospective Comparison of Angiotensin Receptor-Neprilysin Inhibitor (ARNI) with ACE inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) study to a real-world heart failure population.

METHODS AND RESULTS

Medical records of all heart failure patients living within the catchment area of Umeå University Hospital were reviewed. This district consists of around 150 000 people. Out of 2029 patients with a diagnosis of heart failure, 1924 (95%) had at least one echocardiography performed, and 401 patients had an ejection fraction of ≤35% at their latest examination. The major PARADIGM-HF criteria were applied, and 95 patients fulfilled all enrolment criteria and thus were eligible for sacubitril-valsartan. This corresponds to 5% of the overall heart failure population and 24% of the population with ejection fraction ≤ 35%. The eligible patients were significantly older (73.2 ± 10.3 vs. 63.8 ± 11.5 years), had higher blood pressure (128 ± 17 vs. 122 ± 15 mmHg), had higher heart rate (77 ± 17 vs. 72 ± 12 b.p.m.), and had more atrial fibrillation (51.6% vs. 36.2%) than did the PARADIGM-HF population.

CONCLUSIONS

Only 24% of our real-world heart failure and reduced ejection fraction population was eligible for sacubitril-valsartan, and the real-world heart failure and reduced ejection fraction patients were significantly older than the PARADIGM-HF population. The lack of data on a majority of the patients that we see in clinical practice is a real problem, and we are limited to extrapolation of results on a slightly different population. This is difficult to address, but perhaps registry-based randomized clinical trials will help to solve this issue.

Heart Failure: The Dilemma of the 40-50% Ejection Fraction Range

The common pathophysiology contributing to fluid retention and dyspnoea in heart failure is a non-compliant and stiff myocardium with raised left ventricular end-diastolic pressure. With the rapid development of newer imaging technologies, particularly echocardiography, our understanding of the syndrome of heart failure has significantly changed. The most important imaging sign in the early eighties was reduced ejection fraction (HFrEF), with low values being used as an explanation for the development of signs and symptoms.  In the early 2000s, similar Doppler echocardiographic signs became frequently recognised in patients with heart failure symptoms and signs who proved to have  a relatively maintained ejection fraction (EF) of >40%, hence the description of the syndrome of “diastolic heart failure”.  This was later rephrased as heart failure with normal ejection fraction (HFnEF) and more recently as heart failure with preserved ejection fraction (HFpEF). Since then, HFpEF has attracted the interest of many cardiologists and scientists worldwide, searching for specific features and treatment options for the syndrome. As for the features, two important findings have now been established, the first showed that LV systolic function mainly at the subendocardial level was abnormal in HFpEF, particularly manifesting during stress/exercise when the increase in heart rate was not associated with a commensurate increase in stroke volume and a second observation of a significant impairment of left atrial function (i.e. myocardial strain) and emptying fraction associated with increased left atrial pressures and the potential development of atrial arrhythmia in HFpEF. Such atrial abnormalities have been shown to be commonly associated with cavity enlargement and poor compliance. The latter observation has similarly been reported in patients with reduced EF.  Despite the above similarities in cardiac physiology between HFpEF and HFrEF, treatments of the two conditions differ markedly. When comparing HFrEF and HFpEF, we can easily see that some patients fall into the grey area on the EF spectrum with values fluctuating above and below 40%, suggesting that the substrate for the expected drug effect may differ, possibly explaining the lack of consistent response in these patients.. In addition, it should not be forgotten that most heart failure medications work on the circulation rather than the heart itself, hence the need for shared circulatory disturbances between the two conditions before we can reasonably expect identical treatment benefits when using the same medications in different clinical settings.  Therefore, it is clear that classifying heart failure patients according to a single measure of LV function i.e. ejection fraction fails to help at least 50% of patients presenting with this syndrome. In contrast, aggregating such patients based on clear evidence for raised LA pressures, irrespective of EF, might show evidence for a more consistent response to vasodilators and conventional heart failure therapy, particularly those patients currently described as HFpEF. 

Electrocardiographic predictors of peripartum cardiomyopathy

Objective

To identify potential electrocardiographic predictors of peripartum cardiomyopathy (PPCM).

Methods:

This was a case–control study carried out in three hospitals in Kano, Nigeria. Logistic regression models and a risk score were developed to determine electrocardiographic predictors of PPCM.

Results:

A total of 54 PPCM and 77 controls were consecutively recruited after satisfying the inclusion criteria. After controlling for confounding variables, a rise in heart rate of one beat/minute increased the risk of PPCM by 6.4% (p = 0.001), while the presence of ST–T-wave changes increased the odds of PPCM 12.06-fold (p < 0.001). In the patients, QRS duration modestly correlated (r = 0.4; p < 0.003) with left ventricular dimensions and end-systolic volume index, and was responsible for 19.9% of the variability of the latter (R² = 0.199; p = 0.003). A risk score of ≥ 2, developed by scoring 1 for each of the three ECG disturbances (tachycardia, ST–T-wave abnormalities and QRS duration), had a sensitivity of 85.2%, specificity of 64.9%, negative predictive value of 86.2% and area under the curve of 83.8% (p < 0.0001) for potentially predicting PPCM.

Conclusion

In postpartum women, using the risk score could help to streamline the diagnosis of PPCM with significant accuracy, prior to confirmatory investigations

Prevalence and predictors of right ventricular diastolic dysfunction in peripartum cardiomyopathy

BACKGROUND

This study aimed to assess the prevalence of right ventricular diastolic dysfunction (RVDD) and its potential predictors in peripartum cardiomyopathy (PPCM) patients.

METHODS

This was a cross-sectional study carried out in Nigeria. RVDD was defined and graded using Doppler filling and myocardial tissue Doppler velocities obtained at tricuspid annular level.

RESULTS

Forty-three subjects with PPCM and mean age of 26.6 ± 7.0 years were recruited over 6 months. RVDD was found in 30 (69.8 %) subjects, of whom 16 (53.3 %) had grade I, 12 (40.0 %) had grade II and 2 (6.7 %) had grade III severity. RV systolic dysfunction (RVSD), defined as RV fractional area change <35 %, was found in 88.4 %, while combined RVSD and RVDD was found in 58.1 % of patients. Subjects with RVDD had significantly higher tricuspid E/e' ratio (5.1 ± 2.8 versus 3.5 ± 1.0, p = 0.012) and prevalence of pulmonary hypertension (76.7 versus 46.2 %; p < 0.05), and lower serum selenium concentration (55.6 ± 12.1 versus 72.5 ± 12.0 µg/L, p = 0.001) than those with preserved RV diastolic function. Regression analyses showed serum selenium [odds ratio (OR) = 1.14; 95 % confidence interval (CI) = 1.0-1.3; p = 0.049] and combined RVSD and pulmonary hypertension (OR = 79.2; CI = 3.9-1593.7; p = 0.004) as the only predictors of RVDD, and serum selenium <70 µg/L increased the odds of RVDD by 6.67-fold (CI = 1.18-37.78; p = 0.032).

CONCLUSIONS

Both RVDD and RVSD were common in PPCM patients. Selenium deficiency and combined RVSD and pulmonary hypertension seemed to be the only determinants of RVDD in this small cohort, a finding that needs verification in a larger sample of patients.

One Year Survival in Nigerians with Peripartum Cardiomyopathy

BACKGROUND

Peripartum cardiomyopathy (PPCM) is common in North-Western Nigeria. This study aimed to describe the 1-year survival and left ventricular reverse remodeling (LVRR) in a group of patients with PPCM from three referral hospitals in Kano, Nigeria.

METHODS

PPCM was defined according to recommendations of the Heart Failure (HF) Association of the European Society of Cardiology Working Group on PPCM. LVRR was defined as absolute increase in left ventricular ejection fraction (LVEF) by ≥10.0% and decrease in left ventricular (LV) end-diastolic dimension indexed to body surface area ≤33.0 mm/m(2), while recovered LV systolic function as LVEF ≥55%, at 12 months follow-up.

RESULTS

A total of 54 newly diagnosed PPCM patients with mean age of 26.6 ± 6.7 years, presented with classical features of predominantly left-sided HF and 33 of them qualified for follow-up. Of the 17 survivors at 12 months, 8 patients (47.1%) satisfied the criteria for LVRR, of whom 5 (29.4%) had recovered LV systolic function (LVEF ≥55%), but LVRR was not predicted by any variable in the regression models. The prevalence of normal LV diastolic function increased from 11.1% at baseline to 35.3% at 12 months (P = 0.02). At 1-year follow-up, 41.4% of patients had died (two-thirds of them within the first 6 months), but mortality was not predicted by any variable including LVRR.

CONCLUSIONS

In Kano, PPCM patients had modest LVRR but high mortality at 1-year. Further studies should be carried out to identify reasons for the high mortality and how to curb it.

Right ventricular systolic dysfunction and remodelling in Nigerians with peripartum cardiomyopathy: a longitudinal study

Background

The literature on right ventricular systolic dysfunction (RVSD) in peripartum cardiomyopathy (PPCM) patients is scanty, and it appears that RV reverse remodelling in PPCM has not been previously described. This study thus aimed to assess RVSD and remodelling in a cohort of PPCM patients in Kano, Nigeria.

Methods

A longitudinal study carried out in 3 referral hospitals in Kano, Nigeria. Consecutive PPCM patients who had satisfied the inclusion criteria were recruited and followed up for 12 months. RVSD was defined as the presence of either tricuspid annular plane systolic excursion (TAPSE) <16 mm or peak systolic wave (S’) tissue Doppler velocity of RV free wall <10 cm/s. For the purpose of this study, recovery of RV systolic function was defined as an improvement of reduced TAPSE to ≥16 mm or S’ to ≥10 cm/s, without falling to reduced levels again, during follow-up.

Results

A total of 45 patients were recruited over 6 months with a mean age of 26.6 ± 7.0 years. RV systolic function recovery occurred in a total of 8 patients (8/45; 17.8 %), of whom 6 (75.0 %) recovered in 6 months after diagnosis. The prevalence of RVSD fell from 71.1 % at baseline to 36.4 % at 6 months (p = 0.007) and 18.8 % at 1 year (p = 0.0008 vs baseline; p = 0.41 vs 6 month). Patients with RVSD had higher serum creatinine, and TAPSE accounted for 19.2 % (p = 0.008) of the variability of serum creatinine at 6 months. Although 83.3 % of the deceased had RVSD, it didn’t predict mortality in the regression models (p > 0.05).

Conclusion

RVSD and reverse remodelling were common in Nigerians with PPCM, in whom the first 6 months after diagnosis seem to be critical for RV recovery and survival.

Combined electrical and global markers of dyssynchrony predict clinical response to cardiac resynchronization therapy

AIM

To assess potential additional value of global left ventricular (LV) dyssynchrony markers in predicting cardiac resynchronization therapy (CRT) response in heart failure (HF) patients.

METHODS

We included 103 HF patients (mean age 67 ± 12 years, 83% male) who fulfilled the guidelines criteria for CRT treatment. All patients had undergone full clinical assessment, NT-proBNP and echocardiographic examination. Global LV dyssynchrony was assessed using total isovolumic time (t-IVT) and Tei index. On the basis of reduction in the NYHA class after CRT, patients were divided into responders and non-responders.

RESULTS

Prolonged t-IVT [0.878 (range, 0.802-0.962), p = 0.005], long QRS duration [0.978 (range, 0.960-0.996), p = 0.02] and high tricuspid regurgitation pressure drop [1.047 (range, 1.001-1.096), p = 0.046] independently predicted response to CRT. A t-IVT ≥ 11.6 s/min was 67% sensitive and 62% specific (AUC 0.69, p = 0.001) in predicting CRT response. Respective values for a QRS ≥ 151 ms were 66% and 62% (AUC 0.65, p = 0.01). Combining the two variables had higher specificity (88%) in predicting CRT response. In atrial fibrillation (AF) patients, only prolonged t-IVT [0.690 (range, 0.509-0.937), p = 0.03] independently predicted CRT response.

CONCLUSION

Combining prolonged t-IVT and the conventionally used broad QRS duration has a significantly higher specificity in identifying patients likely to respond to CRT. Moreover, in AF patients, only prolonged t-IVT independently predicted CRT response.

Impaired left ventricular systolic function reserve limits cardiac output and exercise capacity in HFpEF patients due to systemic hypertension

OBJECTIVES

Heart failure (HF) patients with preserved left ventricular (LV) ejection fraction (EF) (HFpEF) due to systemic hypertension (SHT) are known to have limited exercise tolerance. Despite having normal EF at rest, we hypothesize that these patients have abnormal systolic function reserve limiting their exercise capacity.

METHODS

Seventeen patients with SHT (mean age 68 ± 9 years) but no valve disease and 14 healthy individuals (mean age of 65 ± 10 years) underwent resting and peak exercise echocardiography using conventional, tissue Doppler and speckle tracking techniques. The differences between resting and peak exercise values were also analyzed (Δ). Exercise capacity was determined as the workload divided by body surface area.

RESULTS

Resting values for left atrial (LA) volume/BSA (r=-0.66, p<0.001) and global longitudinal strain rate (GLSR) in early (e) and late (a) diastole (r=0.47 and 0.46, p<0.05 for both) correlated with exercise capacity. LVEF increased during exercise in normals (mean Δ EF=10 ± 8%) but failed to do so in patients (mean Δ EF=0.6 ± 9%, p<0.001 between groups). LV GLSR during systole (s) also failed to increase with exercise in patients, to the same extent as it did in normals (0.2 ± 0.2 vs. 0.6 ± 0.3 1/s, p<0.001). The difference between rest and exercise (Δ) in LV lateral wall systolic velocity from tissue Doppler (s') (0.71, p<0.001), Δ in cardiac output (r=0.60, p<0.001) and Δ GLSRs (r=0.48, p<0.05) all correlated with exercise capacity independent of changes in heart rate.

CONCLUSION

HFpEF patients with hypertensive LV disease have significantly limited exercise capacity which is related to left atrial enlargement as well as compromised LV systolic function at the time of the symptoms. The limited myocardial systolic function reserve seems to be underlying important explanation for their limited exercise capacity.

Theoretical and experimental aspects of erythrocyte filterability testing; flow acceleration and systemic resistance

Blood cell filterability is an established method in blood rheology. The dynamics at flow onset and its relevance to the data interpretation is, however, not fully known. This paper aims to investigate what controls the length and slope of flow acceleration as the medium accelerates to reach the steady state, and how this phenomenon may interfere with the data output. The acceleration time was not constant. With buffer the steady-state flow showed a logarithmic correlation (p<0.05) versus acceleration time and a linear correlation (p<0.001) versus acceleration slope. With 5% erythrocyte resuspension the steady-state flow instead demonstrated a linear relationship versus acceleration time (p<0.001) and no correlation versus acceleration slope. A cut-off timing of 0.6s is suggested to avoid artifacts associated with flow acceleration. The possible influence on data interpretation from the flow channel systemic resistance was also addressed, and found to significantly underestimate measurable changes in erythrocyte properties from unprocessed flow curves. This was despite the traditional correction for blank filtration flow. Both acceleration and effects from systemic resistance do probably have minor influence on the historic data interpretation but could perhaps be considered in the methodology to sharpen the data output.

D-glucose additive protects against osmotic-induced decrease in erythrocyte filterability

Glucose has long-term effects on erythrocyte filterability owing to sorbitol accumulation and glycosylation of intracellular proteins, but glucose effects prior to these long-term metabolic consequences have not been studied to the same extent. D-glucose is osmotically inert in erythrocytes because of facilitated diffusion. Erythrocyte volume regulation, hemolysis and filterability were studied with reference to effects of glucose derivatives dissolved in water. Control situations were water alone or buffer. Salt-stock dilution by water, D-glucose, or 3-O-M-glucose in water (both 570 mmol/L additives) created volume increases of 4.0 +/- 0.2%, 3.4 +/- 0.5% and 3.3 +/- 0.2%, respectively, whereas L-glucose resulted in a 2.2 +/- 0.4% volume decrease (all p < 0.001 versus baseline, mean values +/- SEM). D-glucose at a final concentration 30 mmol/L did not display any osmotic properties. Despite erythrocyte swelling, electrolyte-free glucose did not induce any significant changes in filterability with either 3-microm or 5-microm filters. 3-O-M-glucose gave a 7.8 +/- 1.4% decrease in 3-microm filterability (mean value +/- SEM, p < 0.001), but not to the same extent as by water alone at the corresponding dilution rate (31.7 +/- 3.5%, mean value +/- SEM, p < 0.001). L-glucose caused a 2.0 +/- 0.8% decrease in filterability across the 5-microm (mean value +/- SEM, p < 0.05), but not with the 3-microm filters. Stressing the glucose transport system further, to simulate the water-like properties of electrolyte-free glucose during intravenous infusion, we found that glucose becomes osmotically active and prevents hemolysis at these extreme concentrations (> 114 mmol/L). We conclude that an in vivo concentration range of D-glucose protects the erythrocytes from a decreased filterability induced by osmotic swelling but without having any osmotic properties.

Narrow-pore flow behavior of blood cells in cardioplegic suspension

Cardioplegia alters the ionic composition of the myocardium and also the blood in a way that may influence the cellular capillary flow behavior. We measured changes in RBC volume and narrow-pore flow resistance of blood cardioplegia versus crystalloid medium. Potassium, magnesium and sodium as osmotic control caused an expected cell shrinkage and reduced the flow resistance through 3 microm pores; however, stressing the osmosis further resulted in increased resistance. No major effects were seen with the 5 microm filters. Twenty percent blood cells in the cardioplegic medium caused a 360% increase in 5 microm pore resistance. There were no obvious additional filterability effects of the cardioplegic additives other than their osmotic patterns. There may be a theoretical advantage in having a cell-free medium in terms of flow resistance. Using blood cardioplegia, a limited hypertonicity may be beneficial in reducing the capillary flow resistance of RBC.

Use of polyester leukocyte elimination filters in blood filterability research

We tested a new routine to eliminate leukocytes for blood rheology measurements using commercial leukocyte absorbing filters (here PALL RC400). These filters were punched out and fitted in smaller chambers through which blood was filtered under controlled suction pressure (< 30 mm Hg). This technique resulted in a very effective leukocyte elimination to 0.0022% but also a platelet reduction to 0.2%. The process causes a small but significant hemolysis with free hemoglobin, of the order of 0.06% of the filtered erythrocytes. A small fraction of the erythrocytes were retained in the filter, versus plasma, to reduce the hematocrit on the order of 1.4%. The leukocyte filtration did not cause any detectable functional trauma to the erythrocytes, measured as micro-pore filterability of normal and glutaraldehyde (GA) hardened erythrocytes. However, when 10% of the erythrocytes were hardened with GA, which caused an increase in pore clogging slope (p < 0.05), the additional passage through the leukocyte elimination filter removed this measured change in clogging. This observation suggests that the leukocyte elimination filter may selectively remove, not only leukocytes and platelets, but also hardened erythrocytes. Reticulocyte counting did not reveal any selective removal of young erythrocytes. In general, we find the presented method reproducible, efficient and easy for eliminating leukocytes for blood rheology research although the risk of removing undeformable erythrocytes must be considered.

Analysis of flow acceleration during erythrocyte filtration: dependence of hematocrit and cell rigidity

At flow onset the blood filtration rate accelerates to a steady state, this may affect the interpretation of red blood cell (RBC) filterability. We studied the acceleration of flow while the pressure is built up across the filter to analyse effects of various hematocrits and RBC rigidity by glutaraldehyde (GA) hardening. This was analysed by a new filtration system with high time resolution and unlimited filtration volume. The system uses a digital balance that samples the accumulated weight (e.g., filtration rate through 5 microns Nucleopore membranes) with on-line computer communication. The filtration is computer controlled via a pneumatic valve. White blood cells (WBC) were removed prior to filtration by a WBC-eliminating filter to avoid clogging artifacts. When flow is initiated a steady state is reached at 0.3-0.4 s. This timing was also tested and confirmed by a video monitoring technique of filtration flow into a horizontal pipette. The digital balance has a mathematical function to reduce the effects of vibration noise; when this function was activated the apparent acceleration was retarded to 1.2 s. With any of these techniques the steady state timing did not vary with the hematocrit, however, the volume of filtered suspension during acceleration varied with both the hematocrit and the GA hardening (p < 0.001). Extrapolation to yield the initial filtration rate from the relative flow curve (RBC suspension divided by buffer flow) varied depending on if the acceleration phase was included or not. In the most unfavourable situation, with GA-hardened RBC, this difference was 340% (p < 0.01). The slope to calculate clogging rate was affected in a similar way. Moreover, with the most GA-hardened RBC a delay in flow onset was observed with this technique. The acceleration phenomenon may cause artifacts in systems employing volume-derived filtration kinetics because of fixed volumes of filtrated medium.