Serum potassium level and mineralocorticoid receptor antagonist dose in a large cohort of chronic heart failure patients.

AIMS: Hyperkalaemia is observed frequently in heart failure (HF) patients and is associated with an impaired prognosis and underuse of mineralocorticoid receptor antagonists (MRAs). However, the effects of serum potassium on prescription of the full guideline recommended daily dose of 50 mg in real-world daily practice are unknown. Therefore, we investigated serum potassium and its association with the prescribed MRA dose in a large cohort of chronic HF patients. METHODS AND RESULTS: A total of 5346 patients with chronic HF with a left ventricular ejection fraction ≤40% from 34 Dutch outpatient HF clinics between 2013 and 2016 were analysed on serum potassium and MRA (spironolactone and eplenerone) dose. Data were stratified by potassium as a serum potassium level <4.0, 4.0 to 5.0 or >5.0 mmol/L. Multivariable logistic regression models were used to assess the association between serum potassium and MRA dose and to adjust for potential confounders. Mean serum potassium was 4.4 ± 0.5 mmol/L and hyperkalaemia (serum potassium >5.0 mmol/L) was present in 399 patients (7.5%). MRA was used in 3091 patients (58.1%). Patients with hyperkalaemia significantly less often received ≥100% of the target dose (50 mg) compared with patients with a serum potassium between 4.0-5.0 mmol/L and <4.0 mmol/L (7.7% vs. 9.5% vs. 13.6% respectively, P = 0.0078). In the multivariable regression analyses, patients with hyperkalaemia were significantly less likely to receive ≥100% of the target dose compared with patients with serum potassium 4.0-5.0 mmol/L (OR 0.38, 95% CI 0.15-0.97, P = 0.044). Additionally, a one unit increase in serum potassium was significantly associated with a lower odds of receiving ≥100% of the target dose (OR 0.69, 95% CI 0.49-0.98, P = 0.036). CONCLUSIONS: In this large registry of real-world chronic HF patients, both an increase in serum potassium and hyperkalaemia were associated with a lower odds of receiving the guideline-recommended MRA dose.

Contemporary use of devices in chronic heart failure in the Netherlands.

AIMS: Despite previous surveys regarding device implantation rates in heart failure (HF), insight into the real-world management with devices is scarce. Therefore, we investigated device implantation rates in HF with reduced left ventricular ejection fraction (LVEF) in 34 Dutch centres. METHODS AND RESULTS: A cross-sectional outpatient registry was conducted in 6666 patients with LVEF < 50% and with information about device implantation available [74 (66-81) years of age; 64% male]. Patients were classified into conventional pacemakers (PM, n = 562), implantable cardioverter defibrillators (ICD, n = 1165), and cardiac resynchronization therapy with defibrillator function (CRT-D, n = 885) or pacemaker function only (CRT-P, n = 248), or no device (n = 3806). Centres were divided into ICD-implanting and CRT-implanting and referral centres. Overall, 17.5% had an ICD, 13.3% CRT-D, 3.7% CRT-P, and 8.4% PM. Of those with LVEF ≤ 30%, 42.5% had ICD or CRT-D therapy. A large variation in implantation rates existed between centres: 3-51% for ICD therapy, 0.3-44% for CRT-D therapy, 0-11% for CRT-P therapy, and 0-25% PM therapy. Implantation centres showed higher implantation rates of ICD, CRT-D, and CRT-P compared with referral centres [36% vs. 25% for defibrillators (ICD or CRT-D) and 17% vs. 9% for CRT devices (CRT-D or CRT-P), respectively, P < 0.001], independently of other factors. A large number of clinical factors were predictive for device usage. Among other, LVEF < 40% and male sex were independent positive predictors for ICD/CRT-D use [odds ratio (OR) = 3.33, P < 0.001; OR = 1.87, P = 0.019, respectively]. Older age was independently associated with less ICD/CRT-D (OR = 0.96 per year, P < 0.001) and more CRT-P/PM use (OR = 1.03 per year, P = 0.006). CONCLUSIONS: In this large Dutch HF registry, less than half of the patients with reduced LVEF received an ICD or CRT, even if LVEF was ≤30%, and a large variation between centres existed. Patients from implantation centres had more often ICD or CRT. More uniformity regarding guideline-based use of device therapy in clinical practice is needed.

The IMPACT Study (Influence of Sensor-Equipped Microcatheters on Coronary Hemodynamics and the Accuracy of Physiological Indices of Functional Stenosis Severity).

BACKGROUND: The Navvus pressure sensor-equipped microcatheter allows to measure functional stenosis severity over a work-horse guidewire and is used as a more feasible alternative to regular sensor-equipped wires. However, Navvus is larger in diameter than contemporary sensor-equipped guidewires and may, thereby, influence functional measurements. The present study evaluates the hemodynamic influence of the Navvus microcatheter. METHODS AND RESULTS: In patients with intermediate coronary stenosis, coronary pressure and flow velocity were measured using a dual sensor-equipped guidewire before and after introduction of Navvus. Patients were randomized to microcatheter-first or guidewire-first measurement. The primary end point was the difference in hyperemic stenosis resistance index between measurements before and after introduction of Navvus. Measurements were completed in 28 patients (28 stenoses). Mean hyperemic stenosis resistance was 0.37±0.19 Hg/cm/s for wire-only assessment and 0.48±0.26 Hg/cm/s after Navvus introduction (P<0.001). Bland-Altman analysis documented a mean bias of +0.11 Hg/cm/s (limits of agreement: -0.13 to 0.36), proportional to mean hyperemic stenosis resistance (Spearman ρ =0.61; P=0.001). Passing-Bablok analysis revealed absence of a constant difference but significant proportional difference between the methods. Mean fractional flow reserve was 0.86±0.06 for wire-only assessment and 0.82±0.07 after Navvus introduction (P<0.001). Bland-Altman analysis documented a mean bias of -0.033 (limits of agreement: -0.09 to 0.03), proportional to mean fractional flow reserve (Spearman ρ =0.40; P=0.036). Passing-Bablok analysis revealed significant constant and proportional differences between methods. Similar results were documented for resting indices of stenosis severity. CONCLUSIONS: Introduction of the Navvus microcatheter leads to clinically relevant stenosis severity overestimation in intermediate stenosis.