Adrenalectomy Lowers Incident Atrial Fibrillation in Primary Aldosteronism Patients at Long Term.

Primary aldosteronism (PA) causes cardiovascular damage in excess to the blood pressure elevation, but there are no prospective studies proving a worse long-term prognosis in adrenalectomized and medically treated patients. We have, therefore, assessed the outcome of PA patients according to treatment mode in the PAPY study (Primary Aldosteronism Prevalence in Hypertension) patients, 88.8% of whom were optimally treated patients with primary (essential) hypertension (PH), and the rest had PA and were assigned to medical therapy (6.4%) or adrenalectomy (4.8%). Total mortality was the primary end point; secondary end points were cardiovascular death, major adverse cardiovascular events, including atrial fibrillation, and total cardiovascular events. Kaplan-Meier and Cox analysis were used to compare survival between PA and its subtypes and PH patients. After a median of 11.8 years, complete follow-up data were obtained in 89% of the 1125 patients in the original cohort. Only a trend (P=0.07) toward a worse death-free survival in PA than in PH patients was observed. However, at both univariate (90.0% versus 97.8%; P=0.002) and multivariate analyses (hazard ratio, 1.82; 95% confidence interval, 1.08-3.08; P=0.025), medically treated PA patients showed a lower atrial fibrillation-free survival than PH patients. By showing that during a long-term follow-up adrenalectomized aldosterone-producing adenoma patients have a similar long-term outcome of optimally treated PH patients, whereas, at variance, medically treated PA patients remain at a higher risk of atrial fibrillation, this large prospective study emphasizes the importance of an early identification of PA patients who need adrenalectomy as a key measure to prevent incident atrial fibrillation.

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.

Within-patient reproducibility of the aldosterone: renin ratio in primary aldosteronism.

The plasma aldosterone concentration:renin ratio (ARR) is widely used for the screening of primary aldosteronism, but its reproducibility is unknown. We, therefore, investigated the within-patient reproducibility of the ARR in a prospective multicenter study of consecutive hypertensive patients referred to specialized centers for hypertension in Italy. After the patients were carefully prepared from the pharmacological standpoint, the ARR was determined at baseline in 1136 patients and repeated after, on average, 4 weeks in the patients who had initially an ARR > or =40 and in 1 of every 4 of those with an ARR <40. The reproducibility of the ARR was assessed with Passing and Bablok and Deming regression, coefficient of reproducibility, and Bland-Altman and Mountain plots. Within-patient ARR comparison was available in 268 patients, of whom 49 had an aldosterone-producing adenoma, on the basis of the "4-corner criteria." The ARR showed a highly significant within-patient correlation (r=0.69; P<0.0001) and reproducibility. Bland-Altman plot showed no proportional, magnitude-related, or absolute systematic error between the ARR; moreover, only 7% of the values, for example, slightly more than what could be expected by chance, fell out of the 95% CI for the between-test difference. The accuracy of each ARR for pinpointing aldosterone-producing adenoma patients was approximately 80%. Thus, although it was performed under different conditions in a multicenter study, the ARR showed a good within-patient reproducibility. Hence, contrary to previously claimed poor reproducibility of the ARR, these data support its use for the screening of primary aldosteronism.

The Hyper-Pract Study : a multicentre survey on the accuracy of the echocardiographic assessment of hypertensive left ventricular hypertrophy in clinical practice.

Left ventricular hypertrophy (LVH) assessed by echocardiography has a relevant impact in clinical decision making in hypertensive patients. We investigated the precision and accuracy of hypertensive LVH determination in current clinical practice by a regional-based survey. The study included 211 patients with essential hypertension consecutively attending six hospital outpatient hypertension clinics in the northern Italian region of Lombardy; all subjects had undergone an echocardiographic examination for hypertension-related problems in a non-academic or research ultrasound laboratory within 2 years. The original echocardiographic report was examined to ascertain whether the diagnosis of LVH was based on calculation of left ventricular (LV) mass according to validated formulae and indexed to body size (primary outcome) and whether LV geometrical patterns and indices of diastolic function were provided (secondary outcome). A total of 211 echocardiograms performed by 120 physicians operating in 73 different hospital and out-of-hospital ultrasound laboratories were collected. Absolute LV mass, LV mass index and relative wall thickness were calculated in 45.5%, 24.6% and 12.3% of the cases, respectively. Parameters of LV diastolic filling were measured in two-thirds of the cases and estimation of E/A ratio was provided by less than 20% of the examinations. This study shows that a large majority of echocardiographic examinations, routinely performed in hypertensive subjects in order to detect cardiac damage, do not report qualifying data on LV mass, LV geometry and diastolic function. These results indicate that a quantitative assessment of LVH and LV function is rarely provided in clinical practice.

Body mass index predicts plasma aldosterone concentrations in overweight-obese primary hypertensive patients.

CONTEXT: Body mass index (BMI) shows a direct correlation with plasma aldosterone concentration (PAC) and urinary aldosterone excretion in normotensive individuals; whether the same applies to hypertensive patients is unknown. OBJECTIVE: Our objective was to determine if BMI predicts PAC and the PAC/plasma renin activity ratio [aldosterone renin ratio (ARR)] in hypertensive patients, and if this affects the identification of primary aldosteronism (PA). DESIGN: This was a prospective evaluation of consecutive hypertensive patients referred nationwide to specialized hypertension centers. MAIN OUTCOME MEASURES: Sitting PAC, plasma renin activity, and the ARR, baseline and after 50 mg captopril orally with concomitant assessment of parameters, including BMI and daily sodium intake, were calculated. RESULTS: Complete biochemical data and a definite diagnosis were obtained in 1125 consecutive patients. Of them 999 had primary (essential) hypertension (PH) and 126 (11.2%) PA caused by an aldosterone-producing adenoma in 54 (4.8%). BMI independently predicted PAC (beta = 0.153; P < 0.0001) in PH, particularly in the overweight-obese, but not in the PA group. Covariance analysis and formal comparison of the raw, and the BMI-, sex-, and sodium intake-adjusted ARR with receiver operator characteristic curves, showed no significant improvement for the discrimination of aldosterone-producing adenoma from PH patients with covariate-adjusted ARR. CONCLUSIONS: BMI correlated with PAC independent of age, sex, and sodium intake in PH, but not in PA patients. This association of BMI is particularly evident in overweight-obese PH patients, and suggests a pathophysiological link between visceral adiposity and aldosterone secretion. However, it does not impact on the diagnostic accuracy of the ARR for discriminating PA from PH patients.

Prospective evaluation of the saline infusion test for excluding primary aldosteronism due to aldosterone-producing adenoma.

BACKGROUND: Data on the performance of the tests used to confirm the diagnosis of primary aldosteronism (PA) are limited. OBJECTIVE: To prospectively investigate the accuracy of the saline infusion test (SIT). METHODS: Three hundred and seventeen (26.9%) out of 1125 patients screened in the PAPY study underwent measurement of plasma aldosterone, cortisol and renin activity after infusion of 2 l of isotonic saline intravenously over 4 h. They comprised patients with a baseline aldosterone/renin ratio (ARR) > 40 and one every four patients not fulfilling such criterion. The area under the receiver-operator characteristic curves (AUC) of aldosterone values after SIT was used as a measure of accuracy for diagnosing PA, aldosterone-producing adenoma (APA) or idiopathic hyperaldosteronism (IHA). RESULTS: One hundred and twenty (37.9%) patients had PA that was due to an APA in 46 (38.3%) and to IHA in 74 (61.7%). No untoward effect occurred with the SIT. The AUC (0.811 +/- 0.026, 0.878 +/- 0.040 and 0.784 +/- 0.034 for identification of PA, APA and IHA, respectively) was higher (P < 0.0001) than that under the diagonal. By sensitivity/specificity versus criterion values plot, the best aldosterone cut-off values for identifying APA and IHA were 6.75 and 6.91 ng/dl, respectively. However, even at these optimal cut-offs, sensitivity and specificity were moderate because of values overlapping between patients with and without the disease. Moreover, there were no differences of AUC and aldosterone cut-offs between APA and IHA. CONCLUSION: In a multicenter study the SIT was safe and specific for excluding PA, but had no place for discriminating between an APA and IHA.

Comparison of the captopril and the saline infusion test for excluding aldosterone-producing adenoma.

We performed a prospective head-to-head comparison of the accuracy of the captopril test (CAPT) and the saline infusion test (SAL) for confirming primary aldosteronism due to an aldosterone-producing adenoma (APA) in patients with different sodium intake. A total of 317 (26.9%) of the 1125 patients screened in the Primary Aldosteronism Prevalence in Italy Study underwent both CAPT and SAL. They were composed of the patients with a high aldosterone/renin ratio baseline and 1 every 4 patients without such criterion. The accuracy of post-CAPT or post-SAL plasma aldosterone values for diagnosing APA was estimated with the area under the receiver operator characteristics curves. Primary aldosteronism was found in 120 patients, of which 46 had an APA. No untoward effect occurred with either test. The area under the receiver operator characteristics curve of plasma aldosterone for both tests was higher (P<0.0001) than that under the diagonal, but the between-test difference was borderline significant (P=0.054). The optimal aldosterone cutoff value for identifying APA was 13.9 and 6.75 ng/dL for the CAPT and SAL, respectively. Even at these cutoffs, sensitivity and specificity were moderate because of overlap of values between patients with and without APA. When examined in relation to sodium intake, the accuracy of the SAL surpassed that of the CAPT in the patients with a sodium intake 7.6 g per day, the SAL offers no advantage over the easier-to-perform CAPT.

A prospective study of the prevalence of primary aldosteronism in 1,125 hypertensive patients.

OBJECTIVES: We prospectively investigated the prevalence of curable forms of primary aldosteronism (PA) in newly diagnosed hypertensive patients. BACKGROUND: The prevalence of curable forms of PA is currently unknown, although retrospective data suggest that it is not as low as commonly perceived. METHODS: Consecutive hypertensive patients referred to 14 hypertension centers underwent a diagnostic protocol composed of measurement of Na+ and K+ in serum and 24-h urine, sitting plasma renin activity, and aldosterone at baseline and after 50 mg captopril. The patients with an aldosterone/renin ratio >40 at baseline, and/or >30 after captopril, and/or a probability of PA (by a logistic discriminant function) > or =50% underwent imaging tests and adrenal vein sampling (AVS) or adrenocortical scintigraphy to identify the underlying adrenal pathology. An aldosterone-producing adenoma (APA) was diagnosed in patients who in addition to excess autonomous aldosterone secretion showed: 1) lateralized aldosterone secretion at AVS or adrenocortical scintigraphy, 2) adenoma at surgery and pathology, and 3) a blood pressure decrease after adrenalectomy. Evidence of excess autonomous aldosterone secretion without such criteria led to a diagnosis of idiopathic hyperaldosteronism (IHA). RESULTS: A total of 1,180 patients (age 46 +/- 12 years) were enrolled; a conclusive diagnosis was attained in 1,125 (95.3%). Of these, 54 (4.8%) had an APA and 72 (6.4%) had an IHA. There were more APA (62.5%) and fewer IHA cases (37.5%) at centers where AVS was available (p = 0.002); the opposite occurred where AVS was unavailable. CONCLUSIONS: In newly diagnosed hypertensive patients referred to hypertension centers, the prevalence of APA is high (4.8%). The availability of AVS is essential for an accurate identification of the adrenocortical pathologies underlying PA.

Renal damage in primary aldosteronism: results of the PAPY Study.

Primary aldosteronism (PA) has been associated with cardiovascular hypertrophy and fibrosis, in part independent of the blood pressure level, but deleterious effects on the kidneys are less clear. Likewise, it remains unknown if the kidney can be diversely involved in PA caused by aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA). Hence, in the Primary Aldosteronism Prevalence in Italy (PAPY) Study, a prospective survey of newly diagnosed consecutive patients referred to hypertension centers nationwide, we sought signs of renal damage in patients with PA and in comparable patients with primary hypertension (PH). Patients (n = 1180) underwent a predefined screening protocol followed by tests for confirming PA and identifying the underlying adrenocortical pathology. Renal damage was assessed by 24-hour urine albumin excretion (UAE) rate and glomerular filtration rate (GFR). UAE rate was measured in 490 patients; all had a normal GFR. Of them, 31 (6.4%) had APA, 33 (6.7%) had IHA, and the rest (86.9%) had PH. UAE rate was predicted (P < 0.001) by body mass index, age, urinary Na+ excretion, serum K+, and mean blood pressure. Covariate-adjusted UAE rate was significantly higher in APA and IHA than in PH patients; there were more patients with microalbuminuria in the APA and IHA than in the PH group (P = 0.007). Among the hypertensive patients with a preserved GFR, those with APA or IHA have a higher UAE rate than comparable PH patients. Thus, hypertension because of excess autonomous aldosterone secretion features an early and more prominent renal damage than PH.

Dynamic testing with high-dose adrenocorticotrophic hormone does not improve lateralization of aldosterone oversecretion in primary aldosteronism patients.

OBJECTIVE: Diagnosing aldosterone-producing adenoma (APA) involves a demonstration of the lateralization of aldosterone oversecretion because adrenal incidentalomas are common in hypertensive individuals and many small-sized APA escape identification with available imaging techniques. However, because of the pulsatile pattern of aldosterone secretion this can be a difficult undertaking. Stimulation of aldosterone secretion before adrenal vein sampling (AVS) can overcome this difficulty, but anecdotal data exist. We, therefore, prospectively investigated the usefulness of AVS with dynamic testing in primary aldosteronism (PA) patients. METHODS: We enrolled 24 consecutive consenting patients with a biochemical diagnosis of PA from a tertiary referral centre to measure the effects of adrenocorticotrophic hormone (ACTH) on selectivity, the lateralization of aldosterone secretion to the APA side, and adverse effects. After correcting the hypokalemia we performed bilateral AVS. After 3 h supine resting, blood was simultaneously obtained from both sides. A high-dose ACTH (250 mug intravenous) bolus was then administered and AVS was repeated after 30 min. RESULTS: AVS was bilaterally selective in 88% of patients; no adverse effects occurred. Of the 21 patients with bilaterally selective AVS, three had idiopathic hyperaldosteronism and 18 an APA that was surgically removed in 12 with an ensuing fall in blood pressure at follow-up. After ACTH patients showed a significant increase (P = 0.007) of aldosterone from contralateral adrenal vein blood, but not from the APA gland. Therefore, lateralization of aldosterone secretion on the APA side did not improve. CONCLUSION: AVS is safe and accurate for identifying APA. However, at a statistical power of 99%, these results do not support the usefulness of high-dose ACTH testing to improve the diagnostic accuracy of AVS.

Prevalence of home blood pressure measurement among selected hypertensive patients: results of a multicenter survey from six hospital outpatient hypertension clinics in Italy.

AIM: The purpose of this study was to evaluate the prevalence of home blood pressure (BP) measurement, the type of devices and accuracy in a large sample of hypertensive patients referred to hospital outpatient hypertension clinics. METHODS: Eight hundred and fifty-five consecutive treated hypertensive patients who attended six specialized centers during a period of 4 months were included. They underwent the following procedures: (i) detailed medical interview by a structured questionnaire; (ii) physical examination; (iii) standard 12-lead electrocardiogram; (iv) BP measurements taken by a validated mercury sphygmomanometer and patient's devices. RESULTS: A total of 640 (74.7%) of 855 patients were regularly performing home BP measurement. These patients were on average younger than those not practising it (58 vs 60 years, p<0.01); men were more numerous than women (58 vs 44%, p=0.03) and had higher educational level. Electronic arm-cuff instruments were the most frequently used devices (58%) followed by wrist devices (19%) and mercury or aneroid sphygmomanometers (23%). Significant correlations were found between BPs measured by validated mercury sphygmomanometers and patients' devices [r=0.85, p<0.0001 for systolic BP (SBP) and r=0.78, p<0.0001 for diastolic BP (DBP)]. Differences 5 mmHg in SBP or DBP were found in 50 and 60% of patients, respectively. CONCLUSIONS: Our findings indicate that: (i) home BP measurement is performed by a majority of treated hypertensives seen in specialized centers; (ii) male gender, age and educational level seem to influence the adoption of home BP monitoring; (iii) electronic arm-cuff devices are the most used instruments; (iv) a notable fraction of patient's devices do not meet the accuracy criteria recommended by US Association for the Advancement of Medical Instrumentation.

Long-term vitamin E supplementation fails to reduce lipid peroxidation in people at cardiovascular risk: analysis of underlying factors.

BACKGROUND: Antioxidant supplementation with vitamin E had no effect in the prevention of cardiovascular diseases (CVD) in three recent large, randomized clinical trials. In order to reassess critically the role of vitamin E in CVD prevention, it is important to establish whether these results are related to a lack of antioxidant action. METHODS: We examined the in vivo antioxidant effect of vitamin E (300 mg/day for about three years) in 144 participants in the Primary Prevention Project (females and males, aged >/= 50 y, with at least one major CV risk factor, but no history of CVD). Urinary 8-epi-PGF2alpha (isoprostane F2alpha-III or 15-F2t-isoP), a validated biomarker of lipid peroxidation, was measured by mass spectrometry. RESULTS: Urinary excretion of 8-epi-PGF2alpha [pg/mg creatinine, median (range)] was 141 (67-498) in treated and 148 (76-561) in untreated subjects (p = 0.10). Taking into account possible confounding variables, multiple regression analysis confirmed that vitamin E had no significant effect on this biomarker. Levels of 8-epi-PGF2alpha were in the normal range for most subjects, except smokers and those with uncontrolled blood pressure or hyperglycemia. CONCLUSIONS: Prolonged vitamin E supplementation did not reduce lipid peroxidation in subjects with major cardiovascular risk factors. The observation that the rate of lipid peroxidation was near normal in a large proportion of subjects may help explain why vitamin E was not effective as an antioxidant in the PPP study and was ineffective for CVD prevention in large scale trials.

Awareness of hypertension guidelines in general practice: a pilot study in Lombardy.

BACKGROUND: An adequate knowledge of hypertension guidelines by primary care physicians is a fundamental step for the improvement of the diagnosis and treatment of hypertension in the general population. The aim of this study was to evaluate, in a local survey in the northern area of Lombardy, the general practitioners' knowledge of the WHO/ISH guidelines. METHODS: A 10-item mail questionnaire based on the 1999 WHO/ISH hypertension guidelines was sent to a sample of 280 primary care physicians. The number of answers in agreement with the guidelines was used as a measure of guidelines knowledge, that was considered adequate if a correct answer to 6 out of 10 questions, in addition to an adequate definition of hypertension, was provided. RESULTS: The analysis was based on 83 returned questionnaires, that means a 29% response rate. Guidelines knowledge was adequate in 23.5% of the total study population and the mean score of correct answers was 5.5 points. A significant negative correlation (r = 0.27, p < 0.05) was observed between the mean score of knowledge and the physician's age. CONCLUSIONS: In a sample of primary care physicians from a northern region of Italy, the hypertension guidelines knowledge is inadequate; the reasons and the extent of this poor awareness will require further studies.