Circulation: Protocols slash delays, improve mortality for aortic dissection
“Occasionally, there is going to be a patient that has something else that is life threatening, aortic dissection is one of those conditions that has a much higher mortality rate than acute MI,” said Harris, who is co-director of the Acute Aortic Dissection Program, and co-director of the Complex Valve Program at the Minneapolis Heart Institute (MHI)/Abbott Northwestern Hospital.
According to the International Registry of Acute Aortic Dissection (IRAD), the average time between emergency room (ER) arrival and the diagnosis of acute aortic dissections is 4.3 hours.
In an effort to accelerate the time between hospital arrival and diagnosis and diagnosis and intervention, Harris and colleagues at the MHI established quality improvement protocols and standardized care measures to improve the clinical outcomes of patients diagnosed with the condition.
Thirty-two community hospitals in Minnesota, North Dakota and Wisconsin participated in the initiative, which used educational programming, protocols and tool-kits to properly diagnose and treat aortic dissection.
First, a multidisciplinary committee made up of cardiologists, CV surgeons, vascular surgeons, cardiac anesthesiologists, radiologists, among others, was formed and began working to improve the delays between presentation and diagnosis and improve patient follow-up after hospital discharge.
Personnel from the committee conducted training sessions for paramedics and ER physicians to help clinicians better notice patients who may be presenting with aortic dissection symptoms, said Harris.
“Aortic dissection is not seen by individuals at smaller centers or community hospitals in the frequency that they would think about it the next time they see a patient present with chest pain,” offered Harris. Therefore, the initiative, which began five years ago, tried to focus on better care for the rather uncommon, but dangerous condition.
The aim of the program was to increase awareness and knowledge of acute aortic dissection, standardize the care process, improve care coordination among multiple disciplines and provide feedback for better patient care.
Prior to the initiative, Harris said that there was a lot of “wasted time” between presentation and diagnosis and diagnosis and intervention of these patients due to the fact that those caring for them did not know the correct process to treat patients with the condition.
“With a condition like MI, physicians remember the steps to follow because you see enough of them and know what to do. For something like aortic dissection, which is a rare condition, it’s also useful to have an algorithm to follow,” he said.
By activating the care process prior to hospital admission and ensuring that patients are presenting to surgery with proper blood pressure (systolic BP between 100 and 120 mmHg and heart rates of 60-80 beats per minute), proper antibiotics and antihypertensive medications and imaging tests, the process is now more efficient and provides better results.
To test the efficacy of the previously mentioned techniques, Harris and colleagues examined outcomes including: time between presentation and diagnosis of aortic dissection; time to OR; beta-blocker use prior to and subsequent to discharge; use of intraoperative transesophageal echocardiography (TEE); and all-cause mortality, prior to (Jan. 1, 2003, to July 31, 2005) and post (Aug. 1, 2005, to Sept. 1, 2009) implementation of the aortic dissection protocols.
During the study, the researchers examined 101 cases of aortic dissection—55 percent of the patients were men and all had an average age of 64 years. Sixty-eight percent of patients had aortic dissection affecting the ascending aorta (Type A) and 76 percent were transferred to the aortic dissection center from community hospitals.
“The most important aspect that we found was that the time it took to make a diagnosis of aortic dissection was reduced by 40 percent,” said Harris. “The time was reduced from 279 minutes to 160 minutes. That is pretty substantial if you think about it, it is basically a two hour time savings.”
Additionally, Harris said the study showed a 30 percent decrease between the time a patient was diagnosed with aortic dissection and the time they presented at the operating room. “This is a condition that has a 1 percent per hour mortality rate," he said. “This was a really significant reduction." The times prior to use of the protocols were 728 minutes compared to 360 minutes after implementation of the protocols. “We’ve cut the time that it takes to get from arrival into the operating room basically in half.”
There was also a 57 percent reduction in average delay times between presentation and surgical intervention.
“Now, the whole process is streamlined so the patient is transferred from the outside hospital, met in the ER and we then decipher the correct course of action,” said Harris. “It provides structure as far as medications go and the timing to get the process in a regular system so everyone knows that for this rare condition, this is what we do.”
The study results also found that prior to the initiation of protocols 85 percent of patients were administered beta blockers at hospital discharge, these numbers rose to 100 percent after use of the protocols.
Lastly, mortality rates were reduced by 43 percent and follow-up of patients after discharge increased from 75 percent to 85 percent.
“While we’ve decreased the morality rates for this condition, it is still at 20 percent,” said Harris. “So the hope would be that by standardizing all the various aspects of care, we could improve these outcomes even further.”
Harris said as more awareness grows around the condition more programs like these will be needed and will be more widely used to help to increase the care of those who present with the condition.