RESUMO
Data were collected on patients admitted to the Queen Elizabeth Hospital Birmingham with type-1 myocardial infarction during 2016 and 2017 inclusively, who were treated by percutaneous intervention and had pre-discharge transthoracic echocardiography. The data were obtained from prospectively maintained hospital databases and records. Echocardiography was performed and reported contemporaneously by accredited echocardiographers. The purpose was to understand the prevalence and characteristics of mitral regurgitation (MR) after acute MI, including patients with ST-elevation (STEMI) and non-ST elevation MI (NSTEMI). MR was observed in 294/1000 patients with the following relative severities: mild = 76%, moderate = 21%, severe = 3% [1]. MR was graded by multiparametric quantification including proximal isolvelocity surface area (PISA), vena contracta (VC), effective regurgitant orifice area (EROA) and regurgitant volume (RVol). Amongst all patients with MR (n=294), PISA was performed in 89/294 (30%), VC 75/294 (26%), EROA in 53/294 (18%) and RVol in 26/294 (9%). Amongst patients with moderate or severe MR (n=70), PISA was performed in 57/70 (81%), VC in 55/70 (79%), EROA in 46/70 (66%) and RVol in 25/70 (36%). Characteristics of MR following acute MI were also assessed including frequency of reported leaflet thickness (259/294 = 88%) and mitral annular calcification (102/294 = 35%). Furthermore, the effect of MI on pre-existing MR was investigated and patients with pre-existing MR who continue to have MR after acute MI were found to have progression of MR by one grade in approximately 25% of cases. Finally, using Cox proportional hazards univariate analysis, significant factors associated with mortality in patients with MR post-MI include age (HR 1.065; 95% CI 1.035-1.096; p<0.001), creatinine clearance, (HR 0.981; 95% CI 0.971-0.991; p<0.001), left ventricular ejection fraction (LVEF) (HR 0.966; 95% CI 0.948-0.984; p<0.001), indexed left ventricular end-diastolic volume (LVEDVi) (HR 1.016; 95% CI 1.003-1.029; p=0.018), indexed left ventricular end-systolic volume (LVESVi) (HR 1.021; 95% CI 1.008-1.034; p=0.001), indexed left atrial volume (HR 1.026; 95% CI 1.012-1.039; p<0.001), and those with intermediate likelihood of pulmonary hypertension (pHTN) (HR 2.223; 95% CI 1.126-4.390; p=0.021); or high likelihood of pHTN (HR 5.626; 95% CI 2.189-14.461; p<0.001). Age and LVEF were found to be independent predictors of mortality on multivariate analysis [1].
RESUMO
Mitral regurgitation (MR) following acute myocardial infarction (AMI) worsens prognosis and reports of prevalence vary significantly. The objective was to determine prevalence, risk factors, and outcomes related to MR following AMI. We identified 1000 consecutive patients admitted with AMI in 2016/17 treated by percutaneous coronary intervention with pre-discharge transthoracic echocardiography. MR was observed in 294 of 1000 (29%), graded as mild (n = 224 [76%]), moderate (n = 61 [21%]) and severe (n = 9 [3%]). Compared with patients without MR, patients with MR were older (70 ± 12 vs 63 ± 13 years; p <0.001), with worse left ventricular ejection fraction (LVEF) (52 ± 15% vs 55 ± 11%; p <0.001) and creatinine clearance (69 ± 33 ml/min vs 90 ± 39 ml/min; p <0.001). They also had higher rates of hypertension (64% vs 55%; p = 0.012), heart failure (3.4% vs 1.1%; p = 0.014), previous MI (28% vs 20%; p = 0.005) and severe flow-limitation in the circumflex (50% vs 33%; p <0.001) or right coronary artery (51% vs 42%; p = 0.014). Prevalence and severity of MR were unaffected by AMI subtype. Revascularization later than 72 hours from symptom-onset was associated with increased likelihood of MR (33% vs 25%; p = 0.036) in patients with non-ST elevation myocardial infarction (NSTEMI). After a mean of 3.2 years, 56 of 288 (19%) patients with untreated MR died. Age and LVEF independently predicted mortality. The presence of even mild MR was associated with increased mortality (p = 0.029), despite accounting for confounders. In conclusion, MR is observed in over one-quarter of patients after AMI and associated with lower survival, even when mild. Prevalence and severity are independent of MI subtype, but MR was more common with delayed revascularization following NSTEMI.
