Research Review: Beta-Blocker Use and Clinical Outcomes after Primary Vascular Surgery: A Nationwide Propensity Score-Matched Study

Peripheral arterial disease (PAD) is a pretty common circulatory issue that is associated with a much higher risk of cardiovascular events from stroke to major amputations. It is proven that hypertension, or abnormally high blood pressure, is extremely widespread among those who suffer from PAD. Because of this, blood pressure control is crucial but the main problem is that the use of this prevention is normally inadequate when it comes to clinical guidelines.

Beta Blockers are a long-established and accepted treatment for hypertension and are considered one of the principal options for certain patients. Nonetheless, this treatment has stirred up a lot of controversies because it has been thought to cause many negative aftereffects. These issues can lead to sporadic and irregular blood flow to one’s arms and legs which is known as claudication. Two studies have since refuted this hypothesis and came to the solution that beta-blockers are actually safe and effective in individuals who are dealing with PAD. These studies show that beta-blockers do not cause irregular claudication and have no effect on walking capacity. Nevertheless, there is an extreme lack of data on the actual safety and effectiveness of this kind of treatment among PAD patients.

The main purpose of this research study was to investigate and look into the clinical end results of symptomatic PAD patients after undergoing the beta-blocker treatment after vascular reconstruction. This research study is classified as a population-based, long-term follow-up study in order to ensure accurate results. The data was collected from the nationwide Danish healthcare and administrative databases. Individual records across different registries were provided thanks to the unique Danish 10-digit identity numbers given to all Danish citizens. The Danish National Health service supplies universal access to hospital care, surgery, general consultations, and more.

An observation study was ultimately performed to evaluate the primary research questions which included the investigation of the beta-blocker treatment and its clinical outcomes after vascular reconstruction. Observational studies are generally best used with real-world data derived largely through randomized trials. One of the main objectives would be to study and research the treatments given to certain patients usually not included in these randomized trials. Through a randomized controlled methodology, the relationship between the dependent variable and the independent variable can be determined. And with data already available and derived from the Danish National Health Service and registry database, it makes it all that much better to conduct this study.

Some of the main differences between the patients who took beta-blockers in comparison to those who did not is that they had a statistically greater risk of being admitted with myocardial infarction (MI) or stroke, with the statistics of 16.4% vs 5.4% and 12.2% vs 9.2% respectively (prior to vascular reconstruction.) However, there were no differences in other variables such as gender, operation type, and socio-economic stance between those who went through beta-blocker treatment and those who did not.

The researchers tried to create a greater balance between these cohorts and fairly examined the impact of beta-blockers by applying a variety of methods. The sample size included patients who previously had vascular surgical or endovascular reconstruction because of atherosclerotic disease from the years 1997 to 2007. The Danish Vascular Registry provided patient identification data and the main goal of the registry included both surveillance and quality of improvement. Researchers in the study decided to not include patients who have died within 30 days of being discharged from the hospital as well as younger patients that were under the age of 40. The reason for eliminating those who passed away within the month of being discharged is that their deaths were highly unlikely to actually be caused by the user or the non-use of the beta-blocker treatment. Those under the age of 40 were part of the minority in the sample size so it was smarter to focus on the 40+ age group to get faster and more accurate results.

The main objectives of the registry are surveillance and quality improvement, which contained 65 potential variables. Also, variables such as socio-economic status, employment status, gross income, educational level, age, gender, comorbidity index, patient history, and more were used. The researchers have done a very fine job of creating a balance between these cohorts and fairly examining beta-blocker impact but this does not eliminate all the concerns and there are a few limitations that still remain. Even though beta-blockers are traditionally used to treat hypertension, it was still not the main treatment choice for patients with hypertension and symptomatic PAD patients during the research. There may be a selection bias since patients who are suffering from hypertension did not receive any beta-blocker treatment. It is known that during the entire study period, there was an average of 45% that were on the beta-blocker treatment.

It is concluded that beta-blocker treatment is directly correlated with the decline of the risk of major amputation compared to those who did not go through the beta-blocker treatment. However, findings also show that it is associated with an increase in the risk of recurrent myocardial infarction and/or stroke. And there is simply not enough data collected and research done to provide any conclusive results in changing the future of beta blocker treatments and tests among symptomatic PAD patients. It’s important to continue the research and collect more data with different sample sizes and variables.

Work Cited

Høgh, A., Lindholt, J.S., Nielsen, H., Jensen, L.P. , and Johnsen, S.P. (2013). Beta-blocker Use and Clinical Outcomes after Primary Vascular Surgery: A Nationwide Propensity Score-Matched Study. European Journal of Vascular and Endovascular Surgery 46(1), 93-102.