Prognostic relevance and clinical features of papillary muscle infarction with mitral regurgitation in patients with ST segment elevation myocardial infarction

Dark papillary muscles sign is a new prognostic indicator in patients with dilated cardiomyopathy: A multi-center study

OBJECTIVES

The prognostic value of left ventricular (LV) papillary muscle anomalies in dilated cardiomyopathy (DCM) patients is unclear. The objective of this study was to evaluate the prognostic significance of LV papillary muscle anomalies in DCM patients using cardiac magnetic resonance (CMR).

METHODS

369 DCM patients who underwent CMR at two Chinese medical facilities from January 2019 to June 2023 were retrospectively and consecutively included in total. The various features of the LV papillary muscles were taken into consideration: thickness, attachment, supernumerary papillary muscles, angles, and signal intensity. The end-systolic signal hypointensity of both papillary muscles in early post-contrast cine CMR images was identified as Dark-Paps. Major adverse cardiac events (MACEs) were assessed, and all patients were followed up.

RESULTS

119 patients (32.2 %) had Dark-Paps and 141 patients (38.2 %) experienced MACE during a median follow-up of 22 months. According to Kaplan-Meier curve analysis, patients who had Dark-Paps had a lower survival rate free from MACE (log-rank, p < 0.001). Dark-Paps maintained an independent predictor of MACE in a multivariate model that included left ventricular ejection fraction (LVEF) and late gadolinium enhancement (LGE) extent (HR: 3.49; p < 0.001). Furthermore, adding Dark-Paps to the multivariate model greatly enhanced the prognostic role of endpoint events (C-statistic improvement: 0.652-0.777, Delong test: p < 0.001).

CONCLUSION

Dark-Paps is a potent independent indicator of major adverse cardiac events in dilated cardiomyopathy patients. In addition, Dark-Paps can provide additional prognostic value over the multivariable baseline clinical model.

Papillary Muscle Infarction by Cardiac MRI in Patients With Mitral Regurgitation

BACKGROUND

Papillary muscle (PM) infarction (PMI) detected by cardiac magnetic resonance imaging (CMR) is associated with poor outcomes. Whether PM parameters provide more value for mitral regurgitation (MR) management currently remains unclear. Therefore, we examined the prognostic value of PMI using CMR in patients with MR.

METHODS

Between March 2018 and July 2023, we retrospectively enrolled 397 patients with MR undergoing CMR. CMR was used to detect PMI qualitatively and quantitively. We also collected baseline clinical, echocardiography, and follow-up data.

RESULTS

Of the 397 patients with MR (52.4 ± 13.9 years), 117 (29.5%) were assigned to the PMI group, with 280 (70.5%) in the non-PMI group. PMI was demonstrated more in the posteromedial PM (PM-PM, 98/117) than in the anterolateral PM (AL-PM, 45/117). Compared with patients without PMI, patients with PMI had a decreased AL-PM (41.5 ± 5.4 vs. 45.6 ± 5.3)/PM-PM diastolic length (35.0 ± 5.2 vs. 37.9 ± 4.0), PM-longitudinal strain (LS, 20.4 ± 6.1 vs. 24.9 ± 4.6), AL-PM-LS (19.7 ± 6.8 vs. 24.7 ± 5.6)/PM-PM-LS (21.2 ± 7.9 vs. 25.2 ± 6.0), and increased inter-PM distance (25.7 ± 8.0 vs. 22.7 ± 6.2, all p < 0.001). Multiple logistic regression analyses identified male sex (odds ratio [OR] = 3.65, 95% confidence interval = 1.881-7.081, p < 0.001) diabetes mellitus (OR/95% CI/p = 2.534/1.13-5.68/0.024), AL-PM diastolic length (OR/95% CI/p = 0.841/0.77-0.92/< 0.001), PM-PM diastolic length (OR/95% CI/p = 0.873/0.79-0.964/0.007), inter-PM distance (OR/95% CI/p = 1.087/1.028-1.15/0.003), AL-PM-LS (OR/95% CI/p = 0.892/0.843-0.94/< 0.001), and PM-PM-LS (OR/95% CI/p = 0.95/0.9-0.992/0.021) as independently associated with PMI. Over a 769 ± 367-day follow-up, 100 (25.2%) patients had arrhythmia. Cox regression analyses indicated that PMI (hazard ratio [HR]/95% CI/p = 1.644/1.062-2.547/0.026), AL-PM-LS (HR/95% CI/p = 0.937/0.903-0.973/0.001), and PM-PM-LS (HR/95% CI/p = 0.933/0.902-0.965/< 0.001) remained independently associated with MR.

CONCLUSIONS

The CMR-derived PMI and LS parameters improve the evaluation of PM dysfunction, indicating a high risk for arrhythmia, and provide additive risk stratification for patients with MR.

Dark papillary muscles sign: a novel prognostic marker for cardiac magnetic resonance

OBJECTIVES

The prognostic role of left ventricular (LV) papillary muscle abnormalities in patients with preserved LV systolic ejection fraction (LVEF) is unknown. We sought to evaluate the prognosis role of LV papillary muscle abnormalities by CMR in patients with ventricular arrhythmias, preserved LVEF with no cardiac disease.

METHODS

A total of 391 patients with > 500/24 h premature ventricular complexes and/or with non-sustained ventricular tachycardia (NSVT), preserved LVEF, and no cardiac disease were enrolled. Different features of LV papillary muscles were considered: supernumerary muscles, papillary thickness, the attachment, late gadolinium enhancement (LGE). Dark-Paps was defined as end-systolic signal hypointensity of both papillary muscles in early post-contrast cine CMR images. Mitral valve prolapse, mitral annular disjunction (MAD), and myocardial LGE were considered.

RESULTS

Dark-Paps was found in 79 (20%) patients and was more frequent in females. It was associated with higher prevalence of mitral valve prolapse and MAD. During a median follow-up of 2534 days, 22 hard cardiac events occurred. At Kaplan-Meier curve analysis, patients with Dark-Paps were at higher risk of events than those without (p < 0.0001). Dark-Paps was significantly associated with hard cardiac events in all the multivariate models. Dark-Paps improved prognostic estimation when added to NSVT (p = 0.0006), to LGE (p = 0.005) and to a model including NSVT+LGE (p = 0.014). Dark-Paps allowed a significant net reclassification when added to NSVT (NRI 0.30, p = 0.03), to LGE (NRI 0.25, p = 0.04), and to NSVT + LGE (NRI 0.32, p  = 0.02).

CONCLUSIONS

In LV papillary muscles, Dark-Paps is a novel prognostic marker in patients with ventricular arrhythmias and preserved ejection fraction.

KEY POINTS

• Papillary muscle abnormalities are seen in patients with ventricular arrhythmias and preserved left ventricular ejection fraction. • Early post-contrast hypointensity of papillary muscles in end-systolic cine images (Dark-Paps) is a novel prognostic marker in patients with ventricular arrhythmias and preserved ejection fraction. • Dark-Paps had an additive prognostic role over late gadolinium enhancement and non-sustained ventricular tachycardia.

Papillary Muscle Involvement during Acute Myocardial Infarction: Detection by Cardiovascular Magnetic Resonance Using T1 Mapping Technique and Papillary Longitudinal Strain

Papillary muscle (PPM) involvement in myocardial infarction (MI) increases the risk of secondary mitral valve regurgitation or PPM rupture and may be diagnosed using late gadolinium enhancement (LGE) imaging. The native T1-mapping (nT1) technique and PPM longitudinal strain (PPM-ls) have been used to identify PPM infarction (iPPM) without the use of the contrast agent. This study aimed to assess the diagnostic performance of nT1 and PPM-ls in the identification of iPPM. Forty-six patients, who performed CMR within 14-30 days after MI, were retrospectively enrolled: sixteen showed signs of iPPM on LGE images. nT1 values were measured within the infarcted area (IA), remote myocardium (RM), blood pool (BP), and anterolateral and posteromedial PPMs and compared using ANOVA. PPM-ls values have been assessed on cineMR images as the percentage of shortening between end-diastolic and end-systolic phases. Higher nT1 values and lower PPM-ls were found in infarcted compared to non-infarcted PPMs (nT1: 1219.3 ± 102.5 ms vs. 1052.2 ± 80.5 ms and 17.6 ± 6.3% vs. 21.6 ± 4.3%; p-value < 0.001 for both), with no significant differences between the nT1 of infarcted PPMs and IA and between the non-infarcted PPMs and RM. ROC analysis demonstrated an excellent discriminatory power for nT1 in detecting the iPPM (AUC = 0.874; 95% CI: 0.784-0.963; p < 0.001). nT1 and PPM-ls are valid tools in assessing iPPM with the advantage of avoiding contrast media administration.

Mitral regurgitation quantified by CMR 4D-flow is associated with microvascular obstruction post reperfused ST-segment elevation myocardial infarction

Objectives

Mitral regurgitation (MR) and microvascular obstruction (MVO) are common complications of myocardial infarction (MI). This study aimed to investigate the association between MR in ST-elevation MI (STEMI) subjects with MVO post-reperfusion. STEMI subjects undergoing primary percutaneous intervention were enrolled. Cardiovascular magnetic resonance (CMR) imaging was performed within 48-hours of initial presentation. 4D flow images of CMR were analysed using a retrospective valve tracking technique to quantify MR volume, and late gadolinium enhancement images of CMR to assess MVO.

Results

Among 69 patients in the study cohort, 41 had MVO (59%). Patients with MVO had lower left ventricular (LV) ejection fraction (EF) (42 ± 10% vs. 52 ± 8%, P < 0.01), higher end-systolic volume (98 ± 49 ml vs. 73 ± 28 ml, P < 0.001) and larger scar volume (26 ± 19% vs. 11 ± 9%, P < 0.001). Extent of MVO was associated with the degree of MR quantified by 4D flow (R = 0.54, P = 0.0003). In uni-variate regression analysis, investigating the association of CMR variables to the degree of acute MR, only the extent of MVO was associated (coefficient = 0.27, P = 0.001). The area under the curve for the presence of MVO was 0.66 (P = 0.01) for MR > 2.5 ml. We conclude that in patients with reperfused STEMI, the degree of acute MR is associated with the degree of MVO.