Incident atrial fibrillation and heart failure in treated hypertensive patients with left ventricular hypertrophy

Background

Hypertension and left ventricular hypertrophy (LVH) are predictors of atrial fibrillation (AF) and heart failure (HF). The incidence rates of AF and HF and especially the combination of these two complications in hypertensive patients with LVH receiving antihypertensive treatment are unknown, and so are the association with risk levels of other cardiovascular diseases and death in hypertensive patients with LVH who develop new onset AF and HF.

Purpose

We aimed to investigate the appearance and severity of AF and HF in 8,702 hypertensive patients aged 55–80 years with LVH receiving antihypertensive treatment in a prospective and randomized clinical trial primarily designed to investigate the preventive effect on a composite endpoint of myocardial infarction, stroke and cardiovascular death.

Methods

Included were patients who had sinus rhythm in ECG and no history of AF or HF when they were randomly allocated to blinded study medication with losartan or atenolol. Additional medication was given with hydrochlorothiazide and calcium antagonist if needed to gain blood pressure control. Incident AF was detected by annual ECGs and from adverse event reports submitted by the 930 clinical investigators. Incident HF was diagnosed according to Framingham criteria. Endpoints including incident HF, myocardial infarction, stroke and cardiovascular death were reported with relevant documentation by the investigators, and adjudicated by an expert endpoint committee.

Results

Incident AF occurred in 679 patients (7.8%) and HF in 246 patients (2.8%) during 4.7±1.1 years mean follow-up. Incident AF was associated with a >4-fold increased risk of developing subsequent HF (HR=4.7; 95% CIs, 3.1–7.0; P<0.001) in multivariable Cox analyses adjusting for age, sex, race, randomized treatment, standard cardiovascular risk factors and incident myocardial infarction. The development of HF as a time-dependent variable was associated with a multivariable-adjusted 3-fold increase of the primary study endpoint (HR=3.11; 95% CIs, 1.52 to 6.39; P<0.001) which was the composite of myocardial infarction, stroke or cardiovascular death.

Incident HF was associated with a >3-fold increased risk of developing subsequent AF (HR=3.3; 95% CIs, 2.3–4.9; P<0.001). This development of AF was associated with more than a 2-fold increase of the composite of myocardial infarction, stroke or cardiovascular death in multivariable Cox analysis (HR=2.26; 95% CIs, 1.09–4.67; P=0.028).

Conclusions

Incident atrial fibrillation and heart failure are associated with increased risk of the other in treated hypertensive patients with left ventricular hypertrophy. These hypertensive patients who subsequently develop both atrial fibrillation and heart failure during antihypertensive treatment have particularly high risk of an additional composite endpoint consisting of myocardial infarction, stroke or cardiovascular death.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): The study originally received support from Merck & Co., Inc.

Studies of the extracytoplasmic function sigma factor PG0162 in Porphyromonas gingivalis

PG0162, annotated as an extracytoplasmic function (ECF) sigma factor in Porphyromonas gingivalis, is composed of 193 amino acids. As previously reported, the PG0162-deficient mutant, P. gingivalis FLL350 showed significant reduction in gingipain activity compared with the parental strain. Because this ECF sigma factor could be involved in the virulence regulation in P. gingivalis, its genetic properties were further characterized. A 5'-RACE analysis showed that the start of transcription of the PG0162 gene occurred from a guanine (G) residue 69 nucleotides upstream of the ATG translation initiation codon. The function of PG0162 as a sigma factor was confirmed in a run-off in vitro transcription assay using the purified rPG0162 and RNAP core enzyme from Escherichia coli with the PG0162 promoter as template. As an appropriate PG0162 inducing environmental signal is unknown, a strain overexpressing the PG0162 gene designated P. gingivalis FLL391 was created. Compared with the wild-type strain, transcriptome analysis of P. gingivalis FLL391 showed that approximately 24% of the genome displayed altered gene expression (260 upregulated genes; 286 downregulated genes). Two other ECF sigma factors (PG0985 and PG1660) were upregulated more than two-fold. The autoregulation of PG0162 was confirmed with the binding of the rPG0162 protein to the PG0162 promoter in electrophoretic mobility shift assay. In addition, the rPG0162 protein also showed the ability to bind to the promoter region of two genes (PG0521 and PG1167) that were most upregulated in P. gingivalis FLL391. Taken together, our data suggest that PG0162 is a sigma factor that may play an important role in the virulence regulatory network in P. gingivalis.

Uptake of Tc-99m sestamibi by brown tumors in a patient with primary hyperparathyroidism

This article discusses a case of Tc-99m sestamibi uptake by brown tumors in a patient with primary hyperparathyroidism. Brown tumors are characteristic tumors of hyperparathyroidism and often have well-defined margins. In this patient with clinical findings of hyperparathyroidism, a retrosternal parathyroid adenoma was identified using Tc-99m sestamibi parathyroid scintigraphy. The adenoma was resected surgically, and the diagnosis was confirmed histopathologically.