This interview is one part of a series based on a conversation with Professor Winfried Randerath, a leading expert within the European sleep world. Other parts of this series:
Q: The Baveno work apparently started in the city bearing its name on the coast of Lago Maggiore in Italy. What prompted this work?
Prof. Randerath: In the town of Baveno, sleep physicians from across Europe joined think tanks focused on important topics in sleep medicine to advance research and care, answering questions like, “Where do we stand today?” or “In which direction and how can we move forward?”
In one such think tank meeting in which I participated focused on the reliance on the apnea-hypopnea index (AHI) as a single parameter for stratifying the severity of obstructive sleep apnea (OSA) and determining the associated need to treat. We felt this simple view of the occurrence of respiratory events was too narrow and failed to reflect the full clinical picture and therefore does not do justice to patients. So, we put forth the idea of further development in the form of an expanded view based on multiple factors.
Q: The modified Baveno classification features a colored grid pattern with a treatment indication for patients ranging from weakest to strongest. How do you see the implementation of this in clinical practice?
Prof. Randerath: Yes, this colored scheme was deliberately developed with the intention of making it as simple as possible, using this traffic light scheme we all know from many contexts. As the criteria now contains more fields—nine compared to four in the first version—this scheme is a little more complex, but the visual red-yellow-green designations can aid its use in everyday situations. The reality in our clinical day-to-day work, which we saw in the retrospective study, is that only a small portion of the clinical population falls into the green section, i.e. the group for which we would say that therapy makes no sense at that point.
Q: Cardiovascular risk is a key factor in the modified Baveno classification. Can you describe how cardiovascular risk should be evaluated?
Prof. Randerath: The first draft of the Baveno classification simply identified at-risk patients based on the presence of poorly controlled blood pressure, atrial fibrillation or heart failure. We then realized this was too general and needed to make it more precise. So, we looked at how the established scheme of the European Society of Cardiology (ESC) approaches risk and developed an updated multistep system for the modified Baveno classification
On the one hand, we have patients who have already experienced cardiac events or have established diseases—they have already suffered a heart attack or have severe hypertension or heart failure. These patients are automatically in a high-risk group.
Then we have patients who do not fall into this category, but who have other risk factors that indicate the potential to develop cardiac disease over the next 10 years. This is how the ESC guideline proceeds, using the SCORE2 -OP that factors in cardiovascular risk and age. We adapted the categorization, which enables individual risk assessment.
This means that for patients who do not yet have any established pre-existing conditions, we look at this constellation, the SCORE2-OP, which includes factors such as smoking, diabetes, hypertension, body weight, gender and, as a result, presents a certain probability, which then tells us whether we have a moderate risk or a high risk of suffering a cardiovascular event in the next 10 years. And that's how we classify the patients.
Q: Another key parameter of the modified Baveno classification is symptomology. What are the key symptoms to consider and how might they be evaluated?
Prof. Randerath: The three key symptoms are sleepiness, insomnia and fatigue. When it comes to sleepiness, we must not forget that about half of patients may only experience mild sleepiness, be completely asymptomatic or have insomnia, the inability to sleep. In these patients, the focus should be on disturbed sleep characterized not by difficulty falling asleep but rather by difficulty maintaining sleep. In other words, they wake up and cannot fall asleep again. The Epworth Sleepiness Scale or an evaluated insomnia questionnaire can allow a quantified risk assessment using numerical values.
In everyday clinical practice, for decision-making between doctors and patients, I think you can be much more liberal. If the patient complains of sleepiness—that they’re always sleepy or fall asleep at every opportunity—or if they complain of not being able to maintain stable sleep, then that would certainly be enough as a symptom to then discuss the adequate treatment.
