The Role of Ambulatory Heart Failure Clinics to Avoid Heart Failure Admissions.

BACKGROUND: There is a complex relationship between heart failure (HF) clinic services and health outcomes. We hypothesized that ambulatory clinic activity may be associated with both hospital admission and also with avoidance of admission. METHODS: A retrospective comparative cohort study was conducted examining activity in an ambulatory HF Clinic. Consecutive clinic visits in 2013 were recorded (n = 1728) and periods of high-intensity utilization (HIU) were identified (n = 128). A HIU period was defined by ≥2 consecutive clinic visits within 30 days, ending after 30 days passed without an additional clinic visit. For each HIU period identified, patient characteristics (n = 107) and all clinic visits (n = 324) were examined. HIU periods were then classified by association with hospital admission (±30 days). RESULTS: In 2013, 18.8% of all clinic visits occurred during HIU periods, involving 13.7% of the clinic population. Thirty-eight percent of HIU periods were associated with 62 total hospital admissions (±30 days), of which 58% (n = 36) were for a primary diagnosis of HF. In addition,17 HIU periods met criteria for admission avoided, and 7 HIU periods occurring after hospital discharge also met criteria for admission avoided. CONCLUSIONS: We identified periods of intensive ambulatory clinic activity dedicated to patients with high burdens of comorbidities and both HF and non-HF-related admissions. These periods were also associated with episodes of successful decongestion with oral diuretics, resulting in avoidance of admission. Identifying HF patients who can be treated successfully or who are likely to require admission may be helpful for allocating clinic resources.

CONTEXTE: Il existe un lien complexe entre les services cliniques relatifs à l'insuffisance cardiaque (IC) et les résultats liés à la santé. Nous avons posé l'hypothèse que l'activité dans les unités de soins ambulatoires pourrait avoir une influence à la fois sur les hospitalisations et sur l'évitement des hospitalisations. MÉTHODOLOGIE: Une étude de cohorte comparative rétrospective a été menée afin d'examiner l'activité dans une unité de soins ambulatoires auprès de patients atteints d'IC. Les visites consécutives effectuées à l'unité de soins en 2013 ont été compilées (n = 1728) et les périodes d'utilisation intensive des services (UIS) ont été relevées (n = 128). Une période d'UIS était définie par au moins 2 visites consécutives à l'unité de soins ambulatoires en l'espace de 30 jours; la période était considérée comme terminée après 30 jours sans nouvelle visite. Pour chaque période d'UIS relevée, les caractéristiques des patients (n = 107) et toutes les visites à l'unité de soins (n = 324) ont été examinées. Les périodes d'UIS ont ensuite été classées en fonction de leur association avec une hospitalisation (± 30 jours). RÉSULTATS: En 2013, 18,8 % de toutes les visites à l'unité de soins ambulatoires étaient rattachées à une période d'UIS et concernaient 13,7 % des patients de l'unité. Au total, 38 % des périodes d'UIS ont été associées à 62 hospitalisations (± 30 jours), dont 58 % (n = 36) étaient liées à un diagnostic primaire d'IC. En outre, 17 périodes d'UIS répondaient aux critères définissant une hospitalisation évitée, et 7 périodes d'UIS survenues après que le patient soit sorti de l'hôpital répondaient aussi aux critères définissant une hospitalisation évitée. CONCLUSIONS: Nous avons relevé des périodes d'activité intensive de l'unité de soins ambulatoires consacrées à des patients présentant un lourd fardeau de comorbidité, ainsi que les hospitalisations liées à l'IC et non liées à l'IC. Ces périodes étaient aussi associées à des épisodes de congestion soulagée grâce à des diurétiques oraux, ce qui a permis d'éviter des hospitalisations. Le repérage des patients atteints d'IC qui peuvent être traités efficacement en consultation externe et de ceux qui risquent de devoir être hospitalisés pourrait permettre d'optimiser l'affectation des ressources des unités de soins.

Cardiac resynchronization therapy in mildly symptomatic heart failure: the earlier the better.

A new era is emerging in the field of complex pacing as a treatment for heart failure. Cardiac resynchronization therapy (CRT) is already established as an effective therapy to improve mortality and functional capacity in patients with moderate-severe heart failure, left ventricular systolic impairment and conduction delay (prolonged QRS duration on surface ECG). Recent evidence has demonstrated that CRT is also an effective treatment for patients with mild heart failure. As the indications for CRT expand, cardiologists face the exciting prospect of exploring where pacemaker technology can help improve patient outcomes across the entire heart failure disease continuum. Enthusiasm for future application needs to be tempered with the practicalities of delivering safe and effective care within the confines of finite healthcare resources.

Potentially detrimental cardiovascular effects of oxygen in patients with chronic left ventricular systolic dysfunction.

BACKGROUND: Although the haemodynamic effects of oxygen in healthy subjects are well documented, there have been no well-controlled studies of the effects of oxygen in patients with heart failure (HF). AIMS: To non-invasively evaluate haemodynamic and neurohumoral effects of oxygen in patients with HF at rest. METHODS AND RESULTS: 13 men with heart failure and left ventricular systolic dysfunction (LVSD) were randomised in a double-blind, placebo-controlled, crossover trial to receive medical air or oxygen (40% and high concentration via Hudson non-rebreathing mask). Haemodynamic measurements were made with applanation tonometry, impedance cardiography and venous occlusion plethysmography. Plasma C-terminal B-type natriuretic peptide and A-type natriuretic peptide were measured. Data were analysed with paired t tests. Cardiac output fell by -0.58 (0.62) l/min on high-flow oxygen compared with -0.02 (0.58) l/min on air, p=0.031. Oxygen caused a reduction in heart rate (-4.02 (4.21) vs 0.41 (5.35) beats/min, respectively, p=0.021) and a trend towards increased systemic vascular resistance (875 (1174) vs 235 (321) dyne/s/m(5), p=0.050). Oxygen led to a paradoxical increase in forearm blood flow (0.513 (0.391) vs 0.024 (0.246) ml/min/100 ml forearm volume on air, p=0.01). Natriuretic peptides were unchanged with oxygen. CONCLUSIONS: High-concentration inhaled oxygen has significant haemodynamic effects in patients with LVSD and mild HF. Such effects may be detrimental in patients with decompensated HF.

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.

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.

Differences in arterial compliance, microvascular function and venous capacitance between patients with heart failure and either preserved or reduced left ventricular systolic function.

BACKGROUND: Up to 50% of patients with the clinical syndrome of heart failure have preserved left ventricular systolic function (HF-PSF). These patients may have abnormalities of ventriculo-vascular coupling, due to increased vascular and ventricular stiffness. METHODS: We compared arterial compliance, microvascular vasodilator function and venous capacitance (VC) in 3 groups of patients (n=12 each) matched for the presence of coronary heart disease: 1) HF and preserved systolic function (HF-PSF), 2) HF and reduced systolic function (HF-RSF) and 3) controls (no HF, PSF). Arterial compliance was assessed by measuring aortic pulse wave velocity (PWV) with applanation tonometry. Cutaneous microvascular function was assessed using Laser Doppler imaging (LDI) coupled with iontophoresis of endothelium-dependent (acetylcholine) and -independent (sodium nitroprusside) vasodilators. VC was measured using venous occlusion plethysmography. RESULTS: PWV was significantly higher in HF-PSF subjects than in both HF-RSF and control groups (10.7 [1.1], 8.9 [1.7] and 8.6 [2.1] m/s respectively, p<0.05). Acetylcholine and nitroprusside induced vasodilatation were equally impaired in HF-PSF and HF-RSF, as compared to controls (p<0.01). VC was higher in HF-RSF subjects compared with HF-PSF subjects (1.75 [0.41], 1.34 [0.34] ml/100 ml forearm vol. respectively, p<0.05). CONCLUSIONS: These findings are consistent with a more marked increase in vascular stiffness in HF-PSF than in HF-RSF and suggest that arterial stiffness, dynamic vasodilator function and venous abnormalities may be implicated in the complex pathophysiology of HF-PSF.

Acute myocardial infarction during pregnancy successfully treated with primary percutaneous coronary intervention.

We report a case of a 40 year old pregnant woman who presented with an acute myocardial infarction (AMI) complicated by ventricular fibrillation. She underwent successful primary percutaneous coronary intervention (PCI). With a tendency towards increased maternal age in developed countries, AMI during pregnancy may become a more frequent occurrence.