Improved adrenal vein sampling from a dedicated programme: experience of a low-volume single centre in Singapore

Prolonged Hypokalemia and Delayed Diagnosis of Primary Aldosteronism: Clinical Course and Risk Factors

CONTEXT

Primary aldosteronism (PA) is a common cause of hypertension (HT). However, diagnosis is often delayed, leading to poorer clinical outcomes. Hypokalemia with HT is characteristic of PA, and is an indication for screening.

OBJECTIVE

We evaluated if patients with PA had prolonged hypokalemia before diagnosis, the subsequent biochemical/clinical control, and factors associated with delayed diagnosis.

METHODS

Our study included all PA patients with hypokalemia diagnosed between 2001 and 2022. Delayed diagnosis was defined as duration of hypokalemia of more than 1 year from first occurrence to first evaluation by a PA specialist. Patients were reassessed post adrenalectomy using the Primary Aldosteronism Surgery Outcomes criteria. We performed multivariable analysis to assess for factors associated with delayed diagnosis.

RESULTS

Among 240 patients with PA who presented with hypokalemia, 122 (51%) patients had delayed diagnosis, with prolonged hypokalemia of median duration 4.5 years (range, 2.4-7.5 years). Patients with delayed diagnosis were older, had longer duration of HT, higher pill burden, lower renal function, and more prevalent cardiovascular disease. Factors associated with delayed diagnosis included older age, presence of hyperlipidemia, and less severe hypokalemia (serum potassium >3.0 mmol/L). Compared to patients with early diagnosis, a lower proportion of those with delayed diagnosis underwent adrenal vein sampling (73% vs 58%) (P < .05). Sixty of 118 (50.8%) nondelayed, and 39 of 122 (32.0%) patients with delayed diagnosis, underwent surgery.

CONCLUSION

Despite manifestation of hypokalemia, many patients with PA fail to be promptly screened. Greater emphasis in HT guidelines, and efforts to improve awareness of PA among primary care physicians, are urgently needed.

Success Rate of Adrenal Venous Sampling and its Determining Factors: Experience of a Single Center in Malaysia

BACKGROUND

Primary hyperaldosteronism has been regarded as the commonest and potentially curable cause of secondary hypertension in up to 80% of cases if this condition is detected early. Laparoscopic adrenalectomy proved to be a promising curable method for primary hyperaldosteronism secondary to aldosterone producing adenoma, while primary hyperaldosteronism secondary to bilateral adrenal hyperplasia requires optimization of medical treatment. Adrenal venous sampling (AVS) has been recommended by the Endocrine Society's guideline in addressing the subtypes of primary hyperaldosteronism. Therefore, determining success rate of AVS in our center is crucial in the management of primary hyperaldosteronism and to prevent redundant procedures. The objectives of this study were to evaluate the success rate of AVS in our center and the associated factors that correlate with the success rate.

METHODS

A retrospective study in a single center, all adult patients who were diagnosed with primary hyperaldosteronism and underwent AVS in our center between 2014 until 2022 were included. Successful samples defined by a selectivity index of ≥2, that is, the ratio of adrenal vein cortisol level to the peripheral vein cortisol level, were evaluated. The baseline demographic characteristics of each patient, technical parameters of AVS, and anatomical parameters of right adrenal vein from the venographic images were evaluated and analyzed to correlate with the outcome of AVS. A P-value of <0.05 was considered statistically significant.

RESULTS

The overall success rate of AVS in our center was 61.3%. The success rate significantly increased to 80.6% in the trained interventional radiologist (IR) group, which represents a single IR who had completed specific training in AVS, compared to non-trained IR group which consisted of a total of 10 IRs without specific AVS training (P = 0.046). The right AVS had lower success rate than the left AVS (64% vs. 94.6%). The type of right adrenal vein pattern showed significant association with the outcome of AVS (P = 0.014). There were 6 types of right adrenal vein patterns observed in our study; Type 1 - gland-like pattern with numerous branches, Type 2 - delta pattern, Type 3 - triangular pattern with central "blush", Type 4 - no discernible pattern and Type 5 - spidery or stellate pattern. The sixth pattern was the hepatic radicles blush with hepatic drainage, for which blood sampling were also collected due to its appearance was frequently indistinguishable from the Type 1 pattern. The results showed Type 2 pattern had the highest incidence (30.5%; 32/105 samples) and Type 5 had the highest success rate (100%; 11/11 samples), while the hepatic radicles blush pattern had the highest incidence in fail samples resulting in the highest failure rate (94.7%; 18/19 samples). The visualization of the inferior emissary vein (IEV) from the venographic images during right AVS had a significant association with the successful AVS (97.5% success rate; 39/40 samples; P = 0.003). Contrariwise, blood sampling withdrawn from the right adrenal vein in the presence of hepatic drainage communication associated with the failure AVS (86.7% failure rate; 26/30 samples; P = 0.001).

CONCLUSIONS

The overall success rate of both AVS in our center was 61.3%, and the success rate was higher in the trained IR group than the non-trained IR group. The visualization of IEV and the type of right adrenal vein patterns were the key determining factors with significant association to the successful right AVS. Conversely, blood sampling withdrawn from the hepatic radicles and hepatic drainage had significant association with the failure right AVS.

Treatment of Primary Aldosteronism and Reversal of Renin Suppression Improves Left Ventricular Systolic Function

INTRODUCTION

Primary aldosteronism (PA) is associated with increased risk of cardiovascular events. However, treatment of PA has not been shown to improve left ventricular (LV) systolic function using the conventional assessment with LV ejection fraction (LVEF). We aim to use speckle-tracking echocardiography to assess for improvement in subclinical systolic function after treatment of PA.

METHODS

We prospectively recruited 57 patients with PA, who underwent 24-h ambulatory blood pressure (BP) measurements and echocardiography, including global longitudinal strain (GLS) assessment of left ventricle, at baseline and 12 months post-treatment.

RESULTS

At baseline, GLS was low in 14 of 50 (28.0%) patients. On multivariable analysis, GLS was associated with diastolic BP (P = 0.038) and glomerular filtration rate (P = 0.026). GLS improved post-surgery by -2.3, 95% CI: -3.9 to -0.6, P = 0.010, and post-medications by -1.3, 95% CI: -2.6 to 0.03, P = 0.089, whereas there were no changes in LVEF in either group. Improvement in GLS was independently correlated with baseline GLS (P < 0.001) and increase in plasma renin activity (P = 0.007). Patients with post-treatment plasma renin activity ≥1 ng/ml/h had improvements in GLS (P = 0.0019), whereas patients with persistently suppressed renin had no improvement. Post-adrenalectomy, there were also improvements in LV mass index (P = 0.012), left atrial volume index (P = 0.002), and mitral E/e' (P = 0.006), whereas it was not statistically significant in patients treated with medications.

CONCLUSION

Treatment of hyperaldosteronism is effective in improving subclinical LV systolic dysfunction. Elevation of renin levels after treatment, which reflects adequate reversal of sodium overload state, is associated with better systolic function after treatment.

CLINICAL TRIAL REGISTRATION

www.ClinicalTrials.gov, identifier: NCT03174847.