Beta-blocker, Shmeta-blocker…Or Are There Important Differences?
SOURCE: Aparicio LS, et al. Comparison of atenolol vs bisoprolol with noninvasive hemodynamic and pulse wave assessment. J Am Soc Hypertens 2015;9:390-396.
Aside from beta-receptor selectivity (beta-1 receptors being involved in cardiac function, beta-2 in pulmonary function), clinicians do not often distinguish major differences within the class of beta-blockers. Alpha-beta-blockers (e.g., carvedilol, labetalol) are not really beta-blockers in the traditional sense because they also provide alpha-receptor blockade. And then there is nebivolol, the nitric-oxide-enhancing beta-blocker associated with — in contrast to most other beta-blockers — peripheral vasodilation. Traditional beta-blockers are associated with peripheral vasoconstriction, which may result in complaints of cold extremities. In 2006, it was brought to the attention of clinicians that while various drugs may lower BP equivalently, they may not always reduce CV endpoints to the same degree. In the ASCOT trial, which compared amlodipine to atenolol, CV outcomes were more favorable with amlodipine, despite similar BP results. The CAFÉ trial (Conduit Artery Function Evaluation) determined that even though arm BP (sometimes called peripheral BP) was similar with either drug (amlodipine or atenolol), central BP (measured at the level of the aorta) was lowered substantially better with amlodipine. Such differences might explain the advantageous outcomes in favor of amlodipine. Aparicio et al compared central BP effects of bisoprolol and atenolol, and found them to be comparable. Whether clinicians should choose pharmacotherapy based upon central BP effects has not been confirmed, although hypertension guidelines throughout the world have increasingly recognized the inadequacy of traditional beta-blockers in comparison to most other classes of agents and relegated them to a lower position on the therapeutic ladder.
Delay in Diagnosis of Hepatocellular Carcinoma
SOURCE: Patel N, et al. Diagnostic delays are common among patients with hepatocellular carcinoma. J Natl Compr Canc Netw 2015;13:543-549.
Hepatocellular carcinoma (HCC) is the third-leading cause of cancer mortality worldwide. It is increasing in the United States, paralleling the rise in non-alcoholic fatty liver disease and hepatitis C. When diagnosed early, the 5-year survival rate is as high as 70%, but diminishes to less than 1 year when diagnosed at an advanced stage. Cirrhosis patients have been suggested to undergo ultrasound screening twice yearly, but not only does this process have only modest sensitivity (32%) it is often not followed by clinicians (or patients). Since 40% of HCC cases present with no previously recognized signs of liver disease, it becomes easier to understand how cases go “under the radar.” Patel et al studied cases of HCC (n = 457) that presented to a large hospital and its affiliated primary care clinics in Dallas between 2005 and 2012. Almost half of the patients had received the HCC diagnosis as inpatients, which was associated with a very short lag time between presentation and diagnosis (< 1 week). For those diagnosed as outpatients (n = 226), the delay from presentation to diagnosis was substantial. For instance, almost 40% of HCC diagnosed among outpatients incurred a 3-month delay from time of presentation, an interval which has been associated with meaningful disease progression. Healthcare sites that employed electronic medical records showed fewer diagnostic delays. There was also a patient-dependent role in diagnostic delay, wherein some patients did not follow up recommended return visits, an occurrence more common among patients with hepatic encephalopathy. The authors encourage timely identification and follow up of persons at-risk for HCC.
Initial Orthostatic Hypotension: An Under-recognized Form of Orthostatic Hypotension
SOURCE: McJunkin B, et al. Detecting initial orthostatic hypotension: A novel approach. J Am Soc Hypertens 2015;9:365-369.
Orthostatic hypotension (OH) is typically defined as a decline in BP > 20/10 mmHg within 3 minutes of standing. OH is consequential not only because of adverse symptoms such as dizziness, blurred vision, or so-called “coat-hanger” headache, but also because it is associated with falls. Fall risk leads to life-changing consequences such as hip fractures and the loss of autonomy due to non-independent living.
A less familiar form of orthostasis is termed initial orthostatic hypotension (IOH). IOH is characterized by a dramatic decline in BP (> 40/20 mmHg) presenting within the first 15 seconds of standing, which self corrects within 30-60 seconds. IOH differs from the normal physiologic experience many of us have had during a transient decrease in BP that recovers by 30 seconds. IOH is a prolongation of recovery time during which patients might experience hypotensive symptoms, or even falls. One of the limitations of prior investigations about IOH has been the delay in BP measurement incurred by simply using 5-10 seconds or more to inflate the BP cuff to measure the BP in the first place. McJunkin et al suggest this obstacle can be obviated by fully inflating the cuff while a patient is supine, allowing immediate deflation and BP measurement upon standing. Among a population of elderly patients (n = 115) 12% were found to have OH, and 3.5% to have IOH. IOH represents a population at risk for falls which may be missed with “traditional” methods of orthostatic BP measurement.