Nonsustained ventricular tachycardia in heart failure with preserved ejection fraction

BACKGROUND

Ventricular tachycardia (VT) is a common arrhythmia in heart failure with reduced ejection fraction but its incidence, predictors, and significance have not been determined in heart failure with preserved ejection fraction (HFpEF).

METHODS

We performed a retrospective review of arrhythmias in two cohorts of patients with an HFpEF diagnosis. Patients in cohort 1 (n = 40) underwent routine arrhythmia surveillance with a 14-day ambulatory electrocardiogram (ECG) monitor. Patients in cohort 2 (n = 85) had cardiac pacemakers and underwent routine device interrogations.

RESULTS

In cohort 1, 13 patients (32.5%) had one or more episodes of nonsustained VT (NSVT) on ambulatory ECG. In cohort 2, 38 patients (44.7%) had NSVT on cardiac pacemaker interrogations. During a median (interquartile range) follow-up of 3.0 (1.6 to 5.1) years, 15 (12%) patients died (20% of patients with NSVT versus 6.8% of those without NSVT; P = .03). In logistic regression analysis, NSVT was associated with a 3.4-fold higher odds of death (95% confidence interval 1.08 to 10.53; P = .04) in HFpEF.

CONCLUSIONS

In conclusion, patients with HFpEF have a relatively high, and possibly underappreciated, burden of NSVT, which confers a higher risk of mortality. The frequent episodes of NSVT in these patients may provide insight into the mechanism of sudden cardiac death in HFpEF.

Glycoprotein IIIA Gene (PIA) Polymorphism and Aspirin Resistance: Is There Any Correlation?

BACKGROUND:

Platelet glycoprotein (GP) IIb/IIIa receptors play an inevitable role in platelet aggregation. The GP IIIa gene is polymorphic ( PIA1/PIA2) and the presence of a PIA2 allele might be associated with an increased risk for acute coronary syndrome (ACS).

OBJECTIVE:

To examine the prevalence of the PIA2 allele in patients with ACS and in subjects with or without aspirin resistance.

METHODS:

The prevalence of the PIA2 allele was assessed in 158 patients with ACS and PIA2 compared with its prevalence in 199 healthy volunteers. The antiplatelet efficacy of aspirin was examined in all patients with ACS, as well as in 69 individuals who had suffered ischemic stroke and in 58 high-risk subjects without any known ischemic vascular events.

RESULTS:

PIA2 prevalence was significantly higher in patients with ACS (59/158) than in the control group (51/199; p < 0.05). Carriers of the PIA2 allele had a significantly higher risk of developing ACS, even after an adjustment to the risk factors (OR 5.74; 95% CI 1.75 to 18.8; p = 0.004). The occurrence of the PIA2 allele was significantly higher among patients with aspirin resistance than in subjects who demonstrated an appropriate response to the drug (allele frequencies, 0.21 vs 0.14; p < 0.05). All patients homozygous for the PIA2 allele had an inadequate platelet response to aspirin.

CONCLUSIONS:

Our results support the hypothesis that carriers of the PIA2 allele might have an increased risk for ACS. PIA2 homozygosity was associated with an inadequate response to aspirin therapy. Our data further suggest that patients with PIA2 allele homozygosity might benefit from antiplatelet therapy based on adenosine diphosphate antagonists throughout secondary treatment for prevention of ACS.

The role of blood rheology in sickle cell disease

Studies performed in the last decades have highlighted the need to better understand the contribution of the endothelium, vascular function, oxidative stress, inflammation, coagulation, hemolysis and vascular adhesion mechanisms to the pathophysiology of acute vaso-occlusive like events and chronic organ damages in sickle cell disease (SCD). Although SCD is a hemorheological disease, a few works focused on the contribution of blood viscosity, plasma viscosity, red blood cell deformability and aggregation in the pathophysiology of SCD. After a brief description of basic hemorheology, the present review focuses on the role of the hemorheological abnormalities in the causation of several SCD complications, mainly in sickle cell anemia and hemoglobin (Hb) SC disease. Several genetic and cellular modulators of blood rheology in SCD are discussed, as well as unresolved questions and perspectives.