Antibodies to malondialdehyde oxidized low-density lipoproteins predict long term cardiovascular mortality in high risk patients.

AIMS: Antibodies to oxidized low-density lipoproteins (oxLDLAbs) are detectable in the serum of patients with and without atherosclerosis, but it is unclear if they play a pathogenic or a protective role in atherogenesis or if they are simply a marker of atherosclerosis. Therefore, in a prospective cohort study we investigated if oxLDLAbs titer predicts cardiovascular (CV) events in high-risk coronary artery disease patients. METHODS AND RESULTS: The titer of IgG antibodies to malondialdehyde modified oxidized low-density lipoproteins was measured in 748 randomly selected patients of the GENICA study who underwent coronary angiography and assessment of incident CV events at follow-up. Patients were classified by oxLDLAbs into a low and a high titer group, corresponding to the first three and the last quartile, respectively. Cardiovascular event-free survival was compared between oxLDLAbs groups by Kaplan-Meier and multivariate technique including propensity score matching analysis. During long-term follow-up (median 7.2 years) CV deaths were observed in 65 patients (11.6%), more commonly in the high than in the low oxLDLAbs group (patients free from CV death 83.1% vs. 89% respectively, p=0.025). The incidence of CV events was also higher in the former than in latter (event-free survival 69.2% vs. 77.7% respectively, p=0.030). CONCLUSIONS: An oxLDLAbs titer above the 75th percentile is a marker of LDL oxidation which predicts a worse CV prognosis at long term follow-up in high-risk Caucasian patients referred for coronary angiography.

Lipoprotein-associated phospholipase A2 activity predicts cardiovascular events in high risk coronary artery disease patients.

OBJECTIVE: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is deemed to play a role in atherosclerosis and plaque destabilization as demonstrated in animal models and in prospective clinical studies. However, most of the literature is either focused on high-risk, apparently healthy patients, or is based on cross sectional studies. Therefore, we tested the hypothesis that serum Lp-PLA2 mass and activity are useful for predicting cardiovascular (CV) events over the coronary atherosclerotic burden and conventional risk factors in high-risk coronary artery disease patients. METHODS AND RESULTS: In a prospective cohort study of 712 Caucasian patients, who underwent coronary angiography and measurement of both Lp-PLA2 mass and activity at baseline, we determined incident CV events at follow-up after splitting the patients into a high and a low Lp-PLA2 mass and activity groups based on ROC analysis and Youden index. Kaplan-Meier and propensity score matching analysis were used to compare CV event-free survival between groups. Follow-up data were obtained in 75% of the cohort after a median of 7.2 years (range 1-12.7 years) during which 129 (25.5%) CV events were observed. The high Lp-PLA2 activity patients showed worse CV event-free survival (66.7% vs. 79.5%, p = 0.023) and acute coronary syndrome-free survival (75.4% vs. 85.6%, p = 0.04) than those in low Lp-PLA2 group. CONCLUSIONS: A high Lp-PLA2 activity implies a worse CV prognosis at long term follow up in high-risk Caucasian patients referred for coronary angiography.

Somatic mutations in the KCNJ5 gene raise the lateralization index: implications for the diagnosis of primary aldosteronism by adrenal vein sampling.

CONTEXT: Somatic mutations in the selectivity filter of KCNJ5 K(+) channel were found to be associated with higher plasma aldosterone concentrations in the patients with an aldosterone-producing adenoma (APA). OBJECTIVE: We investigated whether plasma aldosterone levels and the lateralization index are higher from the side with the APA with the mutation, as compared with those without the mutation. DESIGN: From 170 consecutive APA patients with comprehensive clinical and KCNJ5 data and a conclusive diagnosis, we recruited 91 patients with adrenal vein sampling and follow-up data. We measured CYP11B1 and CYP11B2 mRNA in APA tissue and plasma aldosterone (PAC) and plasma cortisol concentrations (PCC) in adrenal vein blood. To determine whether KCNJ5 mutations affected aldosterone output from the APA, we calculated the lateralization index (defined as the ratio of PAC to PCC at the APA side over the PAC to PCC ratio at the contralateral side). We also calculated two indexes of the aldosterone production from the APA side and the contralateral suppression index. RESULTS: The mRNA content of CYP11B2, but not of CYP11B1, and, accordingly, the lateralization index was higher (29.9 ± 7.4 vs. 10.3 ± 3.6, P < 0.02) in the APA with the mutation than in the APA without the mutation. CONCLUSIONS: APA patients with the somatic KCNJ5 mutations showed a higher production of aldosterone than those without such mutations, which translates in a higher lateralization index. Thus, they are more likely to be identified at adrenal vein sampling and therefore to receive adrenalectomy.

Hyperparathyroidism can be useful in the identification of primary aldosteronism due to aldosterone-producing adenoma.

Hyperparathyroidism represents as a novel feature of primary aldosteronism (PA). Its occurrence in patients with the surgically correctable aldosterone-producing adenoma (APA) and not in those with bilateral adrenal hyperplasia suggested that the measurement of parathyroid hormone could help in differentiating between these subtypes of PA. To test this hypothesis we measured the plasma levels of intact parathyroid hormone, Ca(2+), and several markers of calcium/phosphorus metabolism in 132 hypertensive patients, including 74 with primary (essential) hypertension and 58 consecutive PA patients. Of the latter, 46 were conclusively diagnosed as APA (by finding of lateralized aldosterone excess, pathology, correction of the hyperaldosteronism, and evidence of a fall of blood pressure after adrenalectomy) and 12 as bilateral adrenal hyperplasia. Based on these diagnoses we used the area under the receiver operator characteristic curve analysis to assess the accuracy of serum parathyroid hormone for identifying the PA cases in the whole group and for distinguishing between APA and bilateral adrenal hyperplasia. In this selected population of hypertensive patients for identifying PA cases, the accuracy of serum parathyroid hormone tended to be lower than that of the aldosterone:renin ratio. However, for discriminating between APA and bilateral adrenal hyperplasia patients it was better than that under the identity line and also that for the aldosterone:renin ratio for pinpointing APA cases among patients with PA. Hence, these findings indicate that raised serum parathyroid hormone levels are a feature of APA that can be useful for selecting the PA patients to be submitted to adrenal vein sampling.

The Adrenal Vein Sampling International Study (AVIS) for identifying the major subtypes of primary aldosteronism.

CONTEXT: In patients who seek surgical cure of primary aldosteronism (PA), The Endocrine Society Guidelines recommend the use of adrenal vein sampling (AVS), which is invasive, technically challenging, difficult to interpret, and commonly held to be risky. OBJECTIVE: The aim of this study was to determine the complication rate of AVS and the ways in which it is performed and interpreted at major referral centers. DESIGN AND SETTINGS: The Adrenal Vein Sampling International Study is an observational, retrospective, multicenter study conducted at major referral centers for endocrine hypertension worldwide. PARTICIPANTS: Eligible centers were identified from those that had published on PA and/or AVS in the last decade. MAIN OUTCOME MEASURE: The protocols, interpretation, and costs of AVS were measured, as well as the rate of adrenal vein rupture and the rate of use of AVS. RESULTS: Twenty of 24 eligible centers from Asia, Australia, North America, and Europe participated and provided information on 2604 AVS studies over a 6-yr period. The percentage of PA patients systematically submitted to AVS was 77% (median; 19-100%, range). Thirteen of the 20 centers used sequential catheterization, and seven used bilaterally simultaneous catheterization; cosyntropin stimulation was used in 11 centers. The overall rate of adrenal vein rupture was 0.61%. It correlated directly with the number of AVS performed at a particular center (P = 0.002) and inversely with the number of AVS performed by each radiologist (P = 0.007). CONCLUSIONS: Despite carrying a minimal risk of adrenal vein rupture and at variance with the guidelines, AVS is not used systematically at major referral centers worldwide. These findings represent an argument for defining guidelines for this clinically important but technically demanding procedure.

A stress reaction affects assessment of selectivity of adrenal venous sampling and of lateralization of aldosterone excess in primary aldosteronism.

BACKGROUND: A stress reaction involving increased cortisol release, which has not been documented thus far, might affect the assessment of selectivity of catheterization during adrenal venous sampling (AVS). OBJECTIVE: To investigate whether an ACTH-driven cortisol release occurs during AVS and whether it influences the assessment of selectivity by the step-up of cortisol (plasma cortisol concentrations, PCC) between the adrenal vein blood (PCC(SIDE)) and the inferior vena cava (PCC(IVC)), e.g. the selectivity index (SI). DESIGN AND METHODS: We determined the SI in samples obtained simultaneously at starting AVS (t-15) and again after 15  min (t0) in 34 consecutive patients with proven aldosterone-producing adenoma. We then calculated the SI with PCC(SIDE) obtained at t-15 and at t0, and the PCC(IVC) values obtained at the different time point, thus simulating sequential AVS. RESULTS: The PCC(SIDE) and the SI fell significantly from t-15 to t0 on both the sides. When PCC(SIDE) obtained at t-15 was combined with PCC(IVC) at t0, the SI values were higher than those obtained with simultaneously drawn samples. This led to label as selective more AVS studies than with bilaterally simultaneous data, especially when using higher cutoffs for the SI. CONCLUSIONS: A transient increase in cortisol release from both adrenal glands occurs in the majority of the patients who undergo AVS. This stress reaction can influence the assessment of both the selectivity of the catheterization during the sequential AVS technique and the lateralization of aldosterone excess.

The aldosterone-renin ratio based on the plasma renin activity and the direct renin assay for diagnosing aldosterone-producing adenoma.

BACKGROUND: The screening for primary aldosteronism is based on the aldosterone-renin ratio calculated with the plasma renin activity (PRA) value as denominator. A direct measurement of active renin (DRA) is being used as an alternative to PRA, but its diagnostic performance remains unclear. METHOD: We, therefore compared, head-to-head, the aldosterone-renin ratio based on PRA with that based on DRA, at baseline and after captopril administration, for identifying aldosterone-producing adenoma (APA) in 251 patients of the Primary Aldosteronism Prevalence in hYpertension Study (PAPY). The area under the receiver operator characteristics curves was used for estimating the accuracy of the aldosterone-renin ratio based on either renin assay for identifying APA and for the comparison between tests. RESULTS: The rate of primary aldosteronism was 13.2%; 6.4% of the patients had an APA and 6.8% idiopathic hyperaldosteronism; 218 (86.8%) had primary hypertension. The area under the receiver operator characteristics curve for identifying APA was higher than 0.50 for the aldosterone-renin ratio based on both renin values (0.870 +/- 0.058 for DRA and 0.973 +/- 0.028 for PRA) (P < 0.0001 for both) and did not differ significantly between the aldosterone-renin ratios calculated with either renin assay. For the aldosterone-renin ratio based on DRA, the optimal cutoff value for identifying APA was 27.3 ng/mIU, remarkably similar to that previously determined for the aldosterone-renin ratio based on PRA. CONCLUSION: Thus, the aldosterone-renin ratio based on DRA is a valuable alternative to that based on PRA for detecting APA.

Validation of the SAA-102 home blood pressure monitor according to the protocols of the European Society of Hypertension, the Association for the Advancement of Medical Instrumentation and the British Society of Hypertension.

OBJECTIVE: To determine the accuracy of a new oscillometric home blood pressure (BP) monitor for arm BP measurement, the SAA-102, developed by the Sensacare Company. DESIGN: Evaluation of the SAA-102 was performed using validation protocols of the European Society of Hypertension (ESH), the Association for the Advancement of Medical Instrumentation (AAMI), and the British Hypertension Society (BHS). METHODS: The SAA-102 monitor was assessed on 33 participants according to ESH requirements, which are based on four zones of accuracy differing from the mercury standard by 5, 10, 15 mmHg or more. Then the oscillometric monitor was tested on 85 participants according to AAMI criteria which require a mean device-observers discrepancy within 5+/-8 mmHg. Finally, the electronic device was evaluated on 93 participants according to BHS requirements, which are based on five phases: before-use calibration, in-use assessment, after-use calibration, static device validation and report of the results. RESULTS: The SAA-102 passed all phases of the ESH international protocol for both systolic and diastolic blood pressure (SBP and DBP). The SAA-102 passed also AAMI criteria for SBP and DBP. The mean discrepancy between the SAA-102 and observers was 0.1+/-4.6 and -2.7+/-5.2 mmHg, for SBP and DBP, respectively. According to BHS protocol, the oscillometric monitor achieved final grading of A/A for SBP and DBP, respectively. CONCLUSION: These data show that the SAA-102 device satisfies ESH, AAMI, and BHS protocols for both SBP and DBP and may be recommended for everyday use for BP monitoring at home and in clinical practice.