Conduction abnormalities during dipyridamole stress testing.

Pharmacological stress tests using dipyridamole are considered to be safe. However, cases of atrioventricular (AV) block have been reported. We retrospectively analyzed ECG at baseline and during dipyridamole stress tests of 2010 consecutive patients (patients with second or third degree AV block were excluded). At baseline, 350 (17.4%) patients had conduction abnormalities. Following dipyridamole infusion 16 patients (0.8%) developed a transient change in AV conduction (15 patients) and or sinus arrest (1 patient). Compared to patients without baseline conduction abnormalities, patients with any conduction abnormalities at baseline were at a higher risk for the development of AV block after dipyridamole infusion [0.3% vs 3.14%, respectively; P < .0001].

The prognostic value of heart rate at discharge in acute decompensation of heart failure with reduced ejection fraction.

AIMS: The effect of elevated heart rate (HR) on morbidity and mortality is evident in chronic stable heart failure; data in this regard in acute decompensated heart failure (ADHF) setting are scarce. In this single-centre study, we sought to address the prognostic value of HR and beta-blocker dosage at discharge on all-cause mortality among patients with heart failure and reduced ejection fraction and ADHF. METHODS AND RESULTS: In this retrospective observational study, 2945 patients were admitted for the first time with the primary diagnosis of ADHF between January 2008 and February 2018. Patients were divided by resting HR at discharge into three groups (HR < 70 b.p.m., HR 70-90 b.p.m., and HR > 90 b.p.m.). Evidence-based beta-blockers were defined as metoprolol, bisoprolol, and carvedilol. The doses of prescribed beta-blockers were calculated into a percentage target dose of each beta-blocker and divided to four quartiles: 0 < Dose ≤ 25%, 25% < Dose ≤ 50%, 50% < Dose ≤ 75%, and >75% of the target dose. Cox regression was used to calculate the hazard ratio for various HR categories and adjusting for clinical and laboratory variables. At discharge, 1226 patients had an HR < 70 b.p.m., 1347 patients had an HR at range 70-90 b.p.m., and 372 patients with an HR > 90 b.p.m. The 30 day mortality rate was 2.2%, 3.7%, and 12.1% (P < 0.001), respectively. Concordantly, 1 year mortality rate was 14.6%, 16.7%, and 30.4% (P < 0.001) among patients with HR < 70 b.p.m., HR 70-90 b.p.m., and HR > 90 b.p.m., respectively. The adjusted hazard ratio was significantly increased only in HR above 90 b.p.m. category (hazard ratio, 2.318; 95% confidence interval, 1.794-2.996). CONCLUSIONS: Patients with ADHF and an HR of <90 b.p.m. at discharge had significantly a lower 1 year mortality independent of the dosage of beta-blocker at discharge. It is conceivable to discharge these patients with lower HR.

Pulmonary arterial capacitance in patients with heart failure and reactive pulmonary hypertension.

AIMS: Reactive pulmonary hypertension (PH) is a severe form of PH secondary to left-sided heart failure (HF). Given the structural and functional abnormalities in the pulmonary vasculature that occur in reactive PH, we hypothesized that pulmonary artery capacitance (PAC) may be profoundly affected, with implications for clinical outcome. METHODS AND RESULTS: We studied 393 HF patients of whom 124 (32%) were classified as having passive PH and 140 (36%) as having reactive PH, and 91 patients with pulmonary arterial hypertension (PAH). Mean PAC was highest in patients without PH (4.5 ± 2.1 mL/mmHg), followed by the passive PH group (2.8 ± 1.4 mL/mmHg) and was lowest in those with reactive PH (1.8 ± 0.7 mL/mmHg) (P = 0.0001). PAC and pulmonary vascular resistance (PVR) fitted well to a hyperbolic inverse relationship (PAC = 0.25/PVR, R(2) = 0.70), with reactive PH patients dispersed almost predominantly on the flat part of the curve where a reduction in PVR is associated with a small improvement in PAC. Elevated PCWP was associated with a significant lowering of PAC for any PVR (P = 0.036). During a median follow-up of 31 months, both reactive PH [hazard ratio (HR) 2.59, 95% confidence interval (CI) 1.14-4.46, P = 0.02] and reduced PAC (HR 0.72 per 1 mL/mmHg increase, 95% CI 0.59-0.88, P = 0.001) were independent predictors of mortality. CONCLUSIONS: The development of reactive PH is associated with a marked reduction in PAC. PAC is a strong independent haemodynamic marker of mortality in HF and may contribute to the increased mortality associated with reactive PH.