Prevenzione Primaria: limiti delle linee guida americane

La decisione clinica di iniziare in prevenzione primaria un trattamento farmacologico in un paziente è supportata da linee guida che con degli score dovrebbero fornirci una predizione del rischio futuro di avere un evento cardiovascolare.
Precedenti studi hanno già evidenziato i limiti che possono avere differenti score applicati a differenti popolazioni e anche questo studio, che si basa su linee guida americane, ne conferma la difficoltà.
Sono stati valutati 1475 pazienti che avevano avuto un IMA in età giovanile (50 o meno anni), non in terapia farmacologica, e retrospettivamente è stato eseguito il calcolo del rischio cardiovascolare secondo le linee guida 2013 ACC/AHA e le raccomandazioni 2016 USPSTF. La media del rischio a 10 anni secondo l’ASCVD risk score era di 4,8%, con la maggioranza di pazienti (72%) che aveva uno score < 7,5%. Inoltre la percentuale di pazienti che avevano i criteri di eleggibilità per la terapia con statine era piuttosto bassa: rispettivamente del 49% secondo la classificazione delle linee guida 2013 ACC/AHA e addirittura del 29% secondo le raccomandazioni del 2016 USPSTF. E come accade anche con altri score, ben il 63% delle donne non era eleggibile per il trattamento per entrambe le linee guida.
Che cosa possiamo concludere? Che, mentre non ci sono dubbi su come comportarci per la prevenzione secondaria, meno chiaro è l’approccio da attuare in prevenzione primaria, anche seguendo le linee guida.

Cardiovascular Risk and Statin Eligibility of Young Adults After an MI: Partners YOUNG-MI Registry

Singh A, Collins BL, Gupta A, Fatima A, Qamar A, Biery D, Baez J, Cawley M, Klein J, Hainer J, Plutzky J, Cannon CP, Nasir K, Di Carli MF, Bhatt DL, Blankstein R

J Am Coll Cardiol 2018;71:292-302

BACKGROUND: Despite significant progress in primary prevention, the rate of MI has not declined in young adults.
OBJECTIVES: The purpose of this study was to evaluate statin eligibility based on the 2013 American College of Cardiology/American Heart Association guidelines for treatment of blood cholesterol and 2016 U.S. Preventive Services Task Force recommendations for statin use in primary prevention in a cohort of adults who experienced a first-time myocardial infarction (MI) at a young age.
METHODS: The YOUNG-MI registry is a retrospective cohort from 2 large academic centers, which includes patients who experienced an MI at age ≤50 years. Diagnosis of type 1 MI was adjudicated by study physicians. Pooled cohort risk equations were used to estimate atherosclerotic cardiovascular disease risk score based on data available prior to MI or at the time of presentation.
RESULTS: Of 1,685 patients meeting inclusion criteria, 210 (12.5%) were on statin therapy prior to MI and were excluded. Among the remaining 1,475 individuals, the median age was 45 years, there were 294 (20%) women, and 846 (57%) had ST-segment elevation MI. At least 1 cardiovascular risk factor was present in 1,225 (83%) patients. The median 10-year atherosclerotic cardiovascular disease risk score of the cohort was 4.8% (interquartile range: 2.8% to 8.0%). Only 724 (49%) and 430 (29%) would have met criteria for statin eligibility per the 2013 American College of Cardiology/American Heart Association guidelines and 2016 U.S. Preventive Services Task Force recommendations, respectively. This finding was even more pronounced in women, in whom 184 (63%) were not eligible for statins by either guideline, compared with 549 (46%) men (p < 0.001).
CONCLUSIONS: The vast majority of adults who present with an MI at a young age would not have met current guideline-based treatment thresholds for statin therapy prior to their MI. These findings highlight the need for better risk assessment tools among young adults.

J Am Coll Cardiol 2018;71:292-302