Balancing Overscreening and Underdiagnosis in Secondary Hypertension

Revisiting resistant hypertension: a comprehensive review

Resistant hypertension (RHT) is typically defined as blood pressure that remains above guideline-directed targets despite the use of three anti-hypertensives, usually including a diuretic, at optimal or maximally tolerated doses. It is generally estimated to affect 10-30% of those diagnosed with hypertension, though the true incidence might be lower after one factor in the prevalence of non-adherence. Risk factors for its development include diabetes, obesity and other adverse lifestyle factors, and a diagnosis of RHT confers a greater risk of adverse cardiovascular outcomes, such as stroke, heart failure and mortality. It is essential to exclude pseudoresistance and secondary hypertension and to ensure non-pharmacologic management is optimised prior to consideration of fourth-line anti-hypertensive agents or advanced interventions, such as device therapies. In this review, we will cover the different definitions of RHT, along with the importance of careful diagnosis and management strategies, and discuss newer agents and research needs.

Fibromuscular dysplasia with unilateral renal agenesis

Fibromuscular dysplasia (FMD) is predominantly diagnosed in women and is a congenital malformation damaging the arterial cell walls of numerous arteries, most prominently impacting the renal arteries. Although previously believed to be a disease of young women, older patients have been shown to make up a large percentage of this patient population as well. FMD is underdiagnosed, and the misdiagnosis of this disease has life-threatening consequences. Here, we present the case of a 24-year-old woman with hypertension who did not receive adequate workup until her symptoms were unrelenting. Her hypertension was presumed to be a result of her generalised anxiety disorder. However, once she began to experience vision changes and significant headaches, further workup ensued. This case exemplifies the importance of performing a thorough evaluation of all patients that present with hypertension of unknown origin, especially young women. To decrease the risk of permanent consequences such as strokes, renal failure and even death, the correct diagnosis of FMD is vital.

Imaging studies in pediatric fibromuscular dysplasia (FMD): a single-center experience

BACKGROUND

Fibromuscular dysplasia (FMD) is a non-inflammatory vascular disease that in children unlike in adults shows no sex predilection. FMD is often underdiagnosed, and its pathophysiology is unclear. Delayed diagnosis may lead to refractory hypertension and decreases the chance of successful treatment. Doppler ultrasound (US), magnetic resonance angiography (MRA), computed tomography angiography (CTA), and catheter-based angiography (angiography) are currently used to help make a clinicoradiological diagnosis of FMD. The main aim of the study was to compare the efficacy of imaging modalities which can allow for earlier and improved detection. Furthermore, an anatomical mapping of the location of lesions can help determine the best treatment modalities.

METHODS

All patients with non-syndromic non-inflammatory renovascular hypertension were recruited from the Nephrology Department at the Children's Hospital of Philadelphia (CHOP) and enrolled in the U.S. FMD Registry maintained at the University of Michigan. Clinical presentation and imaging findings on US, CT, and MRI of children diagnosed with FMD were evaluated.

RESULTS

Mean age at diagnosis was 7 ± 4.9 years (4 months-17 years). Family history of hypertension (HTN) (52%), FMD (8.7%), Caucasian (60%), headache (48%), and HTN (80%) were the most prevalent symptom and sign at presentation. Bruits were 100% specific for renal artery stenosis (RAS) diagnosis but were heard in the minority of patients (3 patients, 12%). FMD was mainly unifocal within a single site (68%) or multiple sites (28%) and involved the main or first order renal branch in about 68% of children. Isolated distal lesions beyond the second order branches were found in about 25% of children. US imaging was significantly less sensitive than angiography (28%, p = 0.003). MRA had a better sensitivity (62.5%, p = 0.3) than US. Overall, CTA had the best sensitivity (84.2%, p = 0.4) compared to angiography; however, only angiography showed distal vessel disease.

CONCLUSIONS

Limitations of the study include the sample size and biases-only patients diagnosed with FMD were included in this study and most patients were referred to a pediatric nephrologist for unexplained hypertension. Angiography should be performed as part of the initial work-up of any child suspected of having renovascular FMD, regardless of the findings seen on US, MRA, or CTA.