Dapagliflozin vs. metolazone in heart failure resistant to loop diuretics

BACKGROUND AND AIMS

To examine the decongestive effect of the sodium-glucose cotransporter 2 inhibitor dapagliflozin compared to the thiazide-like diuretic metolazone in patients hospitalized for heart failure and resistant to treatment with intravenous furosemide.

METHODS AND RESULTS

A multi-centre, open-label, randomized, and active-comparator trial. Patients were randomized to dapagliflozin 10 mg once daily or metolazone 5-10 mg once daily for a 3-day treatment period, with follow-up for primary and secondary endpoints until day 5 (96 h). The primary endpoint was a diuretic effect, assessed by change in weight (kg). Secondary endpoints included a change in pulmonary congestion (lung ultrasound), loop diuretic efficiency (weight change per 40 mg of furosemide), and a volume assessment score. 61 patients were randomized. The mean (±standard deviation) cumulative dose of furosemide at 96 h was 977 (±492) mg in the dapagliflozin group and 704 (±428) mg in patients assigned to metolazone. The mean (±standard deviation) decrease in weight at 96 h was 3.0 (2.5) kg with dapagliflozin compared to 3.6 (2.0) kg with metolazone [mean difference 0.65, 95% confidence interval (CI) -0.12,1.41 kg; P = 0.11]. Loop diuretic efficiency was less with dapagliflozin than with metolazone [mean 0.15 (0.12) vs. 0.25 (0.19); difference -0.08, 95% CI -0.17,0.01 kg; P = 0.10]. Changes in pulmonary congestion and volume assessment score were similar between treatments. Decreases in plasma sodium and potassium and increases in urea and creatinine were smaller with dapagliflozin than with metolazone. Serious adverse events were similar between treatments.

CONCLUSION

In patients with heart failure and loop diuretic resistance, dapagliflozin was not more effective at relieving congestion than metolazone. Patients assigned to dapagliflozin received a larger cumulative dose of furosemide but experienced less biochemical upset than those assigned to metolazone.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04860011.

Risk Stratification Guided by the Index of Microcirculatory Resistance and Left Ventricular End-Diastolic Pressure in Acute Myocardial Infarction

BACKGROUND

The index of microcirculatory resistance (IMR) of the infarct-related artery and left ventricular end-diastolic pressure (LVEDP) are acute, prognostic biomarkers in patients undergoing primary percutaneous coronary intervention. The clinical significance of IMR and LVEDP in combination is unknown.

METHODS

IMR and LVEDP were prospectively measured in a prespecified substudy of the T-TIME clinical trial (Trial of Low Dose Adjunctive Alteplase During Primary PCI). IMR was measured using a pressure- and temperature-sensing guidewire following percutaneous coronary intervention. Prognostically established thresholds for IMR (>32) and LVEDP (>18 mm Hg) were predefined. Contrast-enhanced cardiovascular magnetic resonance imaging (1.5 Tesla) was acquired 2 to 7 days and 3 months postmyocardial infarction. The primary end point was major adverse cardiac events, defined as cardiac death/nonfatal myocardial infarction/heart failure hospitalization at 1 year.

RESULTS

IMR and LVEDP were both measured in 131 patients (mean age 59±10.7 years, 103 [78.6%] male, 48 [36.6%] with anterior myocardial infarction). The median IMR was 29 (interquartile range, 17-55), the median LVEDP was 17 mm Hg (interquartile range, 12-21), and the correlation between them was not statistically significant (r=0.15; P=0.087). Fifty-three patients (40%) had low IMR (≤32) and low LVEDP (≤18), 18 (14%) had low IMR and high LVEDP, 31 (24%) had high IMR and low LVEDP, while 29 (22%) had high IMR and high LVEDP. Infarct size (% LV mass), LV ejection fraction, final myocardial perfusion grade ≤1, TIMI (Thrombolysis In Myocardial Infarction) flow grade ≤2, and coronary flow reserve were associated with LVEDP/IMR group, as was hospitalization for heart failure (n=18 events; P=0.045) and major adverse cardiac events (n=21 events; P=0.051). LVEDP>18 and IMR>32 combined was associated with major adverse cardiac events, independent of age, estimated glomerular filtration rate, and infarct-related artery (odds ratio, 5.80 [95% CI, 1.60-21.22] P=0.008). The net reclassification improvement for detecting major adverse cardiac events was 50.6% (95% CI, 2.7-98.2; P=0.033) when LVEDP>18 was added to IMR>32.

CONCLUSIONS

IMR and LVEDP in combination have incremental value for risk stratification following primary percutaneous coronary intervention. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02257294.

Chest pain with less than 20% change in high sensitivity troponin T - a low risk cohort?

Background: Patients with chest pain are risk-stratified using serial high-sensitivity troponin (T) assays (hsTnT). Those with change in (Δ)hsTnT <20% are often categorised as low-risk and are less likely to be managed as acute coronary syndromes (ACS). We sought to characterise such a population of 'low-risk' chest pain presenters.Methods: We performed a retrospective cohort analysis of sequential patients admitted to our centre over a 1-year period with chest pain, absence of ST-elevation, with elevated hsTnT concentrations, and compared demographic, clinical and outcome data according to ΔhsTnT.Results: Three hundred and eleven patients were subdivided by ΔhsTnT [<20% (n = 80), 20-100% (n = 78), >100% (n = 153)]. Baseline demographic data were well-matched across the three subgroups; atrial fibrillation was more common in the two lower magnitude ΔhsTnT groups. Obstructive coronary artery disease (CAD) - while less common in those with ΔhsTnT <20% (66.2%) compared to the 20-100% (73.1%) and >100% (75.9%) groups (p = 0.03) - remained high in this lower risk group, and indeed revascularisation occurred in >60% of patients, equally frequently in all three groups. Using absolute ΔhsTnT ≥9ng/L within the ΔhsTnT <20% group provided incremental value in ruling in ACS, with a positive predictive value of 74.1%. ΔhsTnT was a univariate but not a multivariate predictor of obstructive CAD.Conclusions: Obstructive CAD and need for revascularisation are frequent in chest pain presenters with ΔhsTnT <20%. The increasing focus on hsTnT algorithms to exclude ACS and promote early discharge without adequate clinical risk stratification modelling risks misdiagnosis of patients presenting with acute myocardial ischaemia with a low-level hsTnT rise.

Sacubitril/Valsartan and Mexiletine: A Proarrhythmic Combination?

The uptake of sacubitril/valsartan since the PARADIGM study confirmed its beneficial effects on outcomes over enalapril in chronic systolic heart failure has inevitably led to potential interactions with co-prescribed medications in real-world patients. We report two cases that raise the possibility of an interaction between sacubitril/valsartan and the class Ib anti-arrhythmic mexiletine resulting in proarrhythmic effects. We discuss the pharmacokinetics of both agents and posit potential mechanistic interactions that suggest caution should be used and careful monitoring for (ventricular) arrhythmias applied in patients receiving sacubitril/valsartan and mexiletine.

The Emerging Potential of the Apelin-APJ System in Heart Failure

The apelin-APJ system is a novel neurohormonal pathway, with studies to date suggesting that it may be of pathophysiologic relevance in heart failure and may indeed be a viable therapeutic target in this syndrome. This interest is driven primarily by the demonstration of its vasodilator, inotropic, and aquaretic actions as well as its apparent antagonistic relationship with the renin-angiotensin system. However, its promise is heightened further by the observation that, unlike other and more established cardioprotective pathways, it appears to be down-regulated in heart failure, suggesting that augmentation of this axis may have a powerful effect on the heart failure syndrome. We review the literature regarding the apelin-APJ system in heart failure and suggest areas requiring further research.

How is dilated cardiomyopathy investigated in Scotland? A contemporary survey

BACKGROUND AND AIMS

Dilated cardiomyopathy (DCM) is a common cause of heart failure. The underlying aetiology remains poorly characterised, with ca. 50% labelled 'idiopathic'. We assessed the extent to which the aetiology of DCM is investigated in Scotland, in comparison to European Society of Cardiology (ESC) recommendations.

METHODS AND RESULTS

Questionnaires regarding the use of coronary angiography, use and availability of cardiac magnetic resonance imaging (CMR) and blood/urine panels to investigate the causes of DCM were sent to the heart failure lead in each of the 23 hospitals across Scotland with an established cardiology department; responses were obtained from 21/23 (91.3%). ESC guidelines regarding coronary angiography were adopted in only 8/21 (38.1%). Only 7/21 (33.3%) had easy access to CMR although 14/21 (66.7%) felt it would be a useful test in DCM. The ESC-recommended blood profile was checked routinely in 7/21 (33.3%). Additional blood tests, many of which not currently recommended, were performed in selected centres.

CONCLUSIONS

DCM patients in Scotland are in general unlikely to undergo current ESC-recommended investigation into the underlying aetiology. There is a need for prospective studies to determine the success rate and influence on management and outcome of such multifaceted approaches to investigating the cause of DCM.

High sensitivity troponin T in acute medicine; more questions than answers?

BACKGROUND

Troponin testing in acute medicine is routine. The introduction of a high sensitivity assay (hs Tn T) has created uncertainty regarding the clinical significance of 'abnormal' troponin T levels. The previous assay could not detect troponin levels <30 ng/l.

AIMS AND METHODS

To characterize those with a hs Tn T ≥14 ng/l. Prospective cohort study of consecutive admissions to an acute medical unit.

RESULTS

Troponin was measured in 564 consecutive patients (∼50% of all admissions) over 1 month; was ≥14 ng/l in 224 (40%) of which 220 patients had demographic data for this analysis. Median (inter-quartile range) peak troponin was 47.5 ng/l (24-130) and 36% had a Tn T between 14 and 30 ng/l. Mean [standard deviation (SD)] age was 72 (12) years and 57% were male. Only 44 patients (20%) had an acute myocardial infarction, reflecting the increased sensitivity but reduced specificity of the assay. Prognosis was poor with 31% mortality at 1 year. Over a mean (SD) follow-up of 648 (61) days, there were 87 deaths (40%). Those with a primary non-cardiac diagnosis (n = 126) had poorer survival than those with a primary cardiac diagnosis (n = 94). Troponin elevation related to sepsis conferred a very poor prognosis with 24 deaths (70%) over the follow-up period.

CONCLUSION

Elevated hs Tn T is very common in acute medicine, but myocardial infarction as an explanation is uncommon. Overall, the prognosis is poor with a tendency to worse outcomes in those with a primary 'non-cardiac' diagnosis.

Galectin-3 and cardiac function in survivors of acute myocardial infarction

BACKGROUND

Galectin-3 is a biomarker associated with inflammation and fibrosis that predicts adverse outcome and relates to biomarkers of extracellular matrix turnover in patients with heart failure, particularly when left ventricular (LV) systolic function is preserved. Whether galectin-3 is related to LV remodeling after acute myocardial infarction is unknown.

METHODS AND RESULTS

Circulating galectin-3 and various extracellular matrix biomarkers were measured in 100 patients (age, 58.9±12.0 years; 77% men) admitted with acute myocardial infarction and LV dysfunction, at baseline (mean 46 hours) and at 24 weeks, with cardiac MRI at each time-point. LV remodeling was defined as change in LV end-systolic volume index. Relationships among galectin-3, biomarkers, and LV remodeling were analyzed across the entire cohort, then according to median baseline LV ejection fraction. Galectin-3 levels were elevated in 22 patients (22%) at baseline and increased significantly over time from 14.7±5.5 to 16.3±6.6 ng/mL (P=0.007). Baseline galectin-3 did not correlate with any LV parameters at baseline or change in any parameter over time. Galectin-3 was positively associated with remodeling in patients with supramedian baseline LV ejection fraction (ie, >49.2%; r=0.40; P=0.01) but not when LV ejection fraction was ≤49.2%. Galectin-3 correlated significantly with matrix metalloproteinase-3 and monocyte chemoattractant protein-1 at baseline, biomarkers that have been shown to relate to LV remodeling in this cohort.

CONCLUSIONS

Galectin-3 correlated significantly with certain biomarkers involved in extracellular matrix turnover, although no definite relationship was identified with LV remodeling. Whether galectin-3 plays a pathological role in remodeling remains unclear but merits further study.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00132093.

Interleukin-21--a biomarker of importance in predicting myocardial function following acute infarction?

INTRODUCTION

Following acute myocardial infarction (AMI), the acute inflammatory response contributes to wound healing but also to progressive myocardial injury. Interleukin-21 (IL-21) plays a key role in immunoregulation; whether IL-21 is associated with left ventricular (LV) remodelling after AMI is unknown.

METHODS

Plasma IL-21 concentrations were measured in 100 patients (age 58.9 ± 12.0 years, 77% male) admitted with AMI and LV dysfunction, at baseline (mean 46 h) and again at 24 weeks; cardiac magnetic resonance and measurement of B-type natriuretic peptide, monocyte chemoattractant protein-1, matrix metalloproteinase (MMP)-2, -3, -9, and tissue inhibitor of metalloproteinase (TIMP)-1, -2, -4 occurred at both time-points. Remodelling was defined as change in LV end-systolic volume index (ΔLVESVI).

RESULTS

Plasma IL-21 concentration was unchanged over time (48.1 [SD 35.4]pg/mL at baseline vs. 48.8 [61.3]pg/mL at 24 weeks, p=0.92). Baseline IL-21 correlated significantly with ΔLVESVI (r=0.30, p=0.005) and change in LV end-diastolic volume index (r=0.33, p=0.003). On multivariate analysis, plasma IL-21 was an independent predictor of remodelling. IL-21 was also significantly associated with higher TIMP-4 concentrations and lower MMP-9 concentrations at baseline.

CONCLUSIONS

IL-21 predicts adverse remodelling following AMI in patients with LV dysfunction. Whether it plays a direct pathophysiological role in remodelling merits further study.

Plasma TIMP-4 predicts left ventricular remodeling after acute myocardial infarction

BACKGROUND

Alterations in the balance between matrix metalloproteinases and their endogenous tissue inhibitors (TIMPs) are associated with left ventricular (LV) remodeling after acute myocardial infarction (AMI). No relationships have been identified between TIMPs and serial postinfarction change in LV function.

METHODS AND RESULTS

Plasma concentrations of TIMP-1, -2, -4 were measured at baseline (mean 46 h) and at 24 weeks in 100 patients (age 58.9 ± 12 years, 77% male) admitted with AMI and LV dysfunction, with cardiac magnetic resonance imaging at each time point. TIMP-1 concentration was reduced, whereas TIMP-2 and -4 concentrations were elevated at baseline compared with a reference control population. TIMP-1 decreased and TIMP-2 increased significantly over time; there was an incremental trend in TIMP-4 concentration. Baseline TIMP-4 correlated with change in LV end-systolic volume index (∆LVESVI; r = 0.24; P = .023) and change in LV end-diastolic volume index (∆LVEDVI; r = 0.25; P = .015). ∆TIMP-4 also correlated with ∆LVESVI and with ∆LVEDVI, as did ∆TIMP-2. On multivariable analysis, baseline TIMP-4 concentration was an independent predictor of ∆LVESVI.

CONCLUSIONS

Plasma TIMP-4 concentration, measured early after AMI, may assist in the prediction of LV remodeling and therefore in the assessment of prognosis. Further study of the role of the TIMPs in the pathophysiology of postinfarction remodeling is warranted.

Tissue plasminogen activator antigen predicts medium-term left ventricular end-systolic volume after acute myocardial infarction

Von Willebrand factor (VWF) and tissue plasminogen activator (t-PA) predict adverse cardiovascular outcome following acute myocardial infarction (AMI) and are weakly associated with pre-discharge left ventricular ejection fraction (LVEF). We examined the relationships between VWF, t-PA antigen, matrix metalloproteinase (MMP)-2,-3, and -9, and B-type natriuretic peptide (BNP), and their predictive effect on serial change in LV volumes in a cohort of patients admitted with AMI. Plasma VWF, t-PA antigen, MMP-2,-3,-9, and BNP were measured at a mean 46 h after AMI in 100 patients (mean age 58.9 +/- 12 years, 77% male) with depressed LVEF. Cardiac magnetic resonance (CMR) imaging was then performed. Biomarker measurement and CMR were repeated at 12 and 24 weeks. Plasma concentrations of VWF, BNP and MMP-9 were elevated while t-PA antigen concentration was at the upper limits of normal; over 24 weeks VWF, t-PA antigen, MMP-9 and BNP decreased significantly. Baseline VWF correlated with BNP (r = 0.35, P < 0.001) and MMP-3 (r = 0.24, P = 0.019) as did t-PA antigen (r = 0.27, P = 0.007 for BNP; r = 0.40, P < 0.001 for MMP-3). t-PA antigen, VWF, MMP-3 and BNP were univariate predictors of LV end-systolic volume at 24 weeks; tPA antigen and BNP remained significant independent predictors on multivariate analysis. t-PA antigen and VWF are related to medium-term LV volumes after AMI, and to MMP-3. This novel link between the coagulation-fibrinolysis system and matrix turnover merits further study in understanding the pathophysiology of adverse ventricular remodeling after AMI.

Microvascular obstruction remains a portent of adverse remodeling in optimally treated patients with left ventricular systolic dysfunction after acute myocardial infarction

BACKGROUND

Microvascular obstruction (MO) is associated with large acute myocardial infarction and lower left ventricular (LV) ejection fraction and predicts greater remodeling, but whether this effect is abolished by contemporary antiremodeling therapies is subject to debate. We examined the influence of several infarct characteristics, including MO, on LV remodeling in an optimally treated post-acute myocardial infarction cohort, using contrast-enhanced cardiac magnetic resonance.

METHODS AND RESULTS

One hundred patients (mean age, 58.9+/-12 years, 77%men) underwent contrast-enhanced cardiac magnetic resonance at baseline (approximately 4 days) and at 12 and 24 weeks. The effects on LV remodeling (ie, change in LV end-systolic volume index [DeltaLVESVi]) of infarct site, transmurality, endocardial extent, and the presence of early and late MO were analyzed. Mean baseline infarct volume index decreased from 34.0 (21.2) mL/m(2) to 20.9 (12.9) mL/m(2) at 24 weeks (P<0.001). Infarct site had no influence on remodeling, but greater baseline infarct transmurality (r=0.47, P<0.001) and endocardial extent (r=0.26, P<0.01) were associated with higher DeltaLVESVi. Early MO was seen in 69 patients (69%) and persisted as late MO in 56 patients (56%). Patients with late MO underwent significantly greater remodeling than those without MO (DeltaLVESVi, +4.1 [13.4] versus -7.0 [12.7] mL/m(2), respectively, P=0.001); those with early MO only displayed an intermediate DeltaLVESVi (-4.9 [13.0] mL/m(2)). Importantly, late MO was seen frequently despite optimal coronary blood flow having been restored at angiography.

CONCLUSIONS

Late MO on predischarge contrast-enhanced cardiac magnetic resonance remains an ominous predictor of adverse LV remodeling despite powerful antiremodeling therapy and may be useful in the risk stratification of survivors of acute myocardial infarction.

Drink, drugs, and the QT interval

The effects of several prescription and illicitly-used drugs on electrocardiographic repolarization are well documented, most frequently manifested as prolongation of the corrected QT (QTc) interval. The combination of multiple repolarization-modulating drugs taken in high dosage can occasionally lead to extreme abnormalities of the QTc interval and ST-segment on the surface ECG, which can lead to the erroneous diagnosis of underlying myocardial ischemia and inappropriate treatment. We report on one such case in which the acute management of a syncopal patient was detrimentally influenced by misinterpretation of a very unusual ECG.

Plasma apelin concentration is depressed following acute myocardial infarction in man

AIMS

Apelin, a novel peptide with a putative role in cardiovascular homeostasis, has gained interest as an endogenous inotrope, but has yet to be described following acute myocardial infarction (AMI) in man. We aimed to characterize plasma apelin concentrations following AMI and to examine its relationship with clinical and prognostic biomarkers.

METHODS AND RESULTS

Plasma concentrations of apelin, N-terminal probrain natriuretic peptide (NT-proBNP), norepinephrine, and arginine vasopressin were measured in 100 patients [mean age 58.9 +/- 12 (SD) years, 77% male] admitted with AMI, with echocardiographic left ventricular (LV) ejection fraction <40%, at mean 46 h after admission and at 24 weeks. Cardiac magnetic resonance imaging was performed pre-discharge and at 24 weeks. Thirty-eight subjects with no cardiac history acted as controls. Apelin concentration was reduced early after AMI (0.54 +/- 0.25 vs. 3.22 +/- 3.01 ng/mL, P <0.001) and remained low at 24 weeks, although it did increase significantly from baseline to 0.62 +/- 0.36 ng/mL, P = 0.030. Apelin had no relationship with any parameter of LV function over time. A relationship was found between baseline apelin and norepinephrine (r = 0.26, P = 0.008). Both NT-proBNP and norepinephrine correlated with adverse ventricular function after AMI.

CONCLUSION

Plasma apelin concentration is reduced early after AMI, increases significantly over time, but remains depressed at 24 weeks.

Andersen-Tawil syndrome

Advances in the understanding of genetic aspects of cardiovascular diseases, together with an increase in the availability of genetic analysis, have resulted in not only increased diagnosis of known inherited conditions, but also the identification of novel syndromes. The combination of potassium-sensitive periodic paralysis, ventricular arrhythmias and dysmorphism, initially described by Andersen and Tawil, represents such a novel condition. We report a case in which genetic analysis led to the diagnosis of Andersen-Tawil syndrome after 15 years of protracted non-invasive and invasive investigations from initial presentation to ultimate diagnosis in a young female. In conclusion, we describe the clinical and genetic features of Andersen-Tawil syndrome and demonstrate the utility of genetic testing in the diagnosis of cardiovascular disease.

Relief of Fontan obstruction demonstrated non-invasively by cardiac magnetic resonance imaging

Greater numbers of children with congenital heart disease are surviving to adulthood. The non-invasive assessment and surveillance of these patients, still based primarily on transthoracic echocardiography, has been significantly enhanced by the advent, and more widespread use of, cardiac magnetic resonance imaging. We report on the influence of cardiac magnetic resonance imaging in the initial evaluation of, and response to treatment in, a patient who had developed an obstruction within her Fontan circuit.

Broken pump or leaky filter? Renal dysfunction in heart failure a contemporary review

Renal dysfunction is a frequent and progressive complication of chronic heart failure and is a powerful predictor of cardiovascular mortality. It is intimately associated with cardiovascular disease even in its earliest stages. Although cardiovascular and renal disease share many risk factors, the prognostic implications do not simply reflect widespread atherosclerotic vascular disease as this appears to be as important in those with heart failure secondary to idiopathic dilated cardiomyopathy as it is in those with coronary artery disease. There may be a role in the progression of heart failure, as the deleterious effects of even "mild" renal impairment seem to be borne out in predicting outcome, in a broad range of heart failure patients including those with heart failure and preserved systolic function. Renal dysfunction is both an indication for, as well as frequently limiting intervention with intensive disease modifying therapy. Although renal impairment is common in heart failure and these patients are at higher risk for adverse events including death, they are under represented in clinical trials.

Epidemiology of heart failure and left ventricular dysfunction after acute myocardial infarction

The development of heart failure and/or left ventricular systolic dysfunction has long been regarded as an ominous complication, significantly increasing the morbidity and short- and long-term mortality of survivors of acute myocardial infarction. Although the incidence of heart failure after myocardial infarction has fallen over the last few decades, it remains common, complicating up to 45% of infarcts. Moreover, up to 60% of myocardial infarcts will result in left ventricular systolic dysfunction, depending on the exact definition used. Those at greatest risk of developing heart failure are the elderly, females, and those with prior myocardial infarction. Advances in the management of acute myocardial infarction have led to reduced in-hospital mortality (even when complicated by heart failure), but longer-term mortality remains high in these patients.

Epidemiology of heart failure and left ventricular systolic dysfunction after acute myocardial infarction: prevalence, clinical characteristics, and prognostic importance

The development of heart failure and/or left ventricular systolic dysfunction (LVSD) in the setting of acute myocardial infarction (AMI) results in significant risk far above that of AMI independently. In patients admitted to the hospital for AMI, concomitant heart failure and/or LVSD on hospital admission or development of either or both of these conditions during admission are among the strongest predictors of inhospital death and are associated with significant increases in inhospital, 30-day, and long-term mortality and rehospitalization rates. Given the high risks in this population, aggressive treatment, comprising early initiation and sustained use of evidence-based treatments, is essential for improving prognosis.