Applicability of Echocardiographic Strict Negative Criteria for Suspected Infective Endocarditis

Echocardiography is the cornerstone imaging technique in the diagnosis of infective endocarditis (IE) but is often misused in clinical practice. Recently, strict negative criteria have been proposed to avoid unnecessary follow-up echocardiograms. We aimed to evaluate the use of echocardiography in real-world clinical daily practice and the usefulness of these criteria in the diagnosis of IE. We retrospectively retrieved every echocardiogram performed in our center for suspected IE between 2014 and 2018, including 905 transthoracic echocardiograms (TTEs). Of these, 451 (49.8%) fulfilled the strict negative criteria (group 1). In this group, IE was seldom diagnosed (n = 4, 0.9%). In 338 patients (37.4%) no signs of IE were evident, but they did not fulfill the strict negative criteria (group 2). A follow-up echocardiogram and definitive diagnosis of IE were more frequent (n = 48, 14.2% and n = 20, 5.9%). Finally, in 116 patients (12.8%) the initial TTE showed typical or suggestive signs of IE, in whom the diagnosis was confirmed in 48 patients (41.4%). A definitive diagnosis of IE was established in a minority of the study population (n = 72, 8%). Only 1 readmission for underdiagnosis of IE was noted on group 2. We conclude that in a real-life setting only a minority of patients in whom IE was suspected had a definitive diagnosis. An initial TTE for suspected IE fulfilling the strict negative criteria predicts both a low probability of requesting a follow-up study and of a definitive diagnosis of IE.

Exercise ECG Testing and Stress Cardiac Magnetic Resonance for Risk Prediction in Patients With Chronic Coronary Syndrome

PURPOSE

Vasodilator stress cardiac magnetic resonance (VS-CMR) has become crucial in the workup of patients with known or suspected chronic coronary syndrome (CCS). Whether traditional exercise ECG testing (ExECG) contributes prognostic information beyond VS-CMR is unclear.

METHODS

We retrospectively included 288 patients with known or suspected CCS who had undergone ExECG and subsequent VS-CMR in our institution. Clinical, ExECG, and VS-CMR variables were recorded. We defined the serious adverse events (SAE) as a combined endpoint of acute coronary syndrome, admission for heart failure, or all-cause death.

RESULTS

During a mean follow-up of 4.2 ± 2.15 yr, we registered 27 SAE (15 admissions for acute coronary syndrome, eight admissions for heart failure, and four all-cause deaths). Once adjusted for clinical, ExECG, and VS-CMR parameters associated with SAE, the only independent predictors were HRmax in ExECG (HR = 0.98: 95% CI, 0.96-0.99; P = .01) and more extensive stress-induced perfusion defects (PDs, number of segments) in VS-CMR (HR = 1.19: 95% CI, 1.07-1.34; P < .01). Adding HRmax significantly improved the predictive power of the multivariable model for SAE, including PDs (continuous reclassification improvement index: 0.47: 95% CI, 0.10-0.81; P < .05). The annualized SAE rate was 1% (if PD < 2 segments and HRmax > 130 bpm), 2% (if PD < 2 segments and HRmax ≤ 130 bpm), 3.2% (if PD ≥ 2 segments and HRmax > 130 bpm), and 6.3% (if PD ≥ 2 segments and HRmax ≤ 130 bpm), P < .01, for the trend. In patients on β-blocker therapy, however, only PDs in VS-CMR, but not HRmax, predicted SAE.

CONCLUSIONS

We conclude that ExECG contributes significantly to prognostic information beyond VS-CMR in patients with known or suspected CCS.

Downstream testing after exercise ECG stress test – can we predict ischemia on subsequent vasodilator stress cardiac magnetic resonance?

Background

Exercise ECG stress test (ExECG) is useful in the diagnostic work-up of patients with chest pain and known or suspected stable ischemic heart disease (SIHD). However, current guidelines recommend a stress imaging, ischemia-detecting technique such as vasodilator stress cardiac magnetic resonance (vs-CMR) if available. Whether clinical and ExECG variables can predict ischemia on subsequent vs-CMR testing is unknown.

Material and methods

We retrospectively included 289 patients who underwent an ExECG and a subsequent vs-CMR in the year after this test and who didn't undergo a revascularization procedure in this time frame. Clinical, ExECG and vs-CMR variables were included in the registry. vs-CMR was considered positive if ischemia was evident in at least one myocardial segment on stress first-pass perfusion without concomitant necrosis on late gadolinium enhancement imaging. We performed univariate and multivariate analysis to check for the association of variables with the risk of ischemia on vs-CMR.

Results

Mean time from ExECG to vs-CMR was 97,27±88,31 days and 91 vs-CMR were positive for ischemia. Age, male sex, diabetes mellitus, hypertension, dyslipidaemia and personal history of ischemic heart disease, percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) were predictors of ischemia on vs-CMR in the univariate analysis. On ExECG, time of exercise, exercise capacity, chest pain during ExECG, maximum heart rate (HR) and systolic blood pressure (SBP), % of predicted HR, chronotropic reserve index, maximum and reserve of double product and Duke Treadmill Score were also associated with ischemia on vs-CMR. However, the only independent predictors on multivariate binary logistic regression stepwise analysis were history of PCI (HR 3.79 [2.03–7.09], p&lt;0.001) or CABG (HR 5.57 [1.80–17.26], p=0.003), maximum double product (HR 0.94 [0.90–0.99] per 1000 increase, p=0.02) and Duke Treadmill Score (HR 0.95 [0.91–0.99], p=0.019). Subgroup analysis showed that male sex (HR 1.95 [1.16–3.28], p=0.012), history of ischemic heart disease (HR 4.73 [2.88–7.76], p&lt;0.001) and maximum double product (HR 0.94 [0.90–0.98] per 1000 increase, p=0.006) were predictors of ischemia on vs-CMR in non-revascularized patients (n=212). In revascularized patients (n=77) the only independent predictor was the Duke Treadmill Score on ExECG (HR 0.93 [0.86–0.99], p=0.048).

Conclusions

Several ExECG variables, namely Duke Treadmill Score and parameters of myocardial oxygen consumption such as maximum doble product, can predict the risk of ischemia on subsequent vs-CMR in revascularized and non-revascularized patients with chest pain. This can help select patients who should undergo vs-CMR afeter ExECG for ischemia detection.

Funding Acknowledgement

Type of funding sources: None.

Exercise ECG testing in patients without known ischemic heart disease: predictors of ischemia of downstream vasodilator stress cardiac magnetic resonance

Background

In routine clinical practice, patients with chest pain and suspected stable ischemic heart disease (SIHD) usually undergo an exercise ECG stress test (ExECG) for ischemia detection. However, since the sensitivity of this technique is relatively low, concerns exist that many patients could remain underdiagnosed. We intend to assess the clinical and ExECG predictors of ischemia on subsequent vasodilator stress cardiac magnetic resonance (vs-CMR) to help select which patients should undergo downstream testing after an initial ExECG.

Material and methods

We retrospectively included 197 patients without previous history of ischemic heart disease who underwent an ExECG and a subsequent vs-CMR in the year after this test and who didn't undergo a revascularization procedure in this time frame. Clinical, ExECG and vs-CMR variables were included in the registry. vs-CMR was considered positive if ischemia was evident in at least one myocardial segment on stress first-pass perfusion without concomitant necrosis on late gadolinium enhancement imaging. We performed univariate and multivariate analysis to check for the association of variables with the risk of ischemia on vs-CMR.

Results

Mean time from ExECG to vs-CMR was 88.69±84.32 days and 37 vs-CMR were positive for ischemia. Male sex, less exercise time, less % of maximum predicted exercise capacity, less maximum double product (heart rate x systolic blood pressure) and less double product reserve (DPR = maximum double product - basal double product) were associated with ischemia on vs-CMR on univariate analyses. However, the only independent predictors of ischemia on vs-CMR on multivariate binary logistic regression were male sex (HR 2.62 [CI 95%: 1.13–5.76], p=0.016) and less DPR (HR 0.90 [CI 95%: 0.84–0.97] per 1000 increase, p=0.006). The risk score derived from these two variables had a moderate predictive power (ROC curves, AUC 0.657, p=0.003). The best cut-off point for the DPR was 12400, as derived from the Youden index. It allowed stratification of the risk of ischemia on vs-CMR, which ranged from 9% in women with &gt;12400 DPR, 18.8% in men with &gt;12400 DPR, 24.1% in women with ≤12400 DPR to 42.9% in men with ≤12400 DPR (p=0.005, Figure 1).

Conclusions

Male sex and less double product reserve on ExECG can moderately predict the risk of ischemia on subsequent vs-CMR in patients presenting with chest pain and without previous SIHD. This can help select patients who benefit most from vs-CMR for diagnostic purposes.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Clinical applicability of echocardiographic strict negative criteria for suspected infective endocarditis

Introduction

Infective endocarditis (IE) is an uncommon but potentially lethal disease that requires a timely diagnosis. Echocardiography has a pivotal role in EI diagnosis, but this may lead to an overuse of this technology in clinical daily practice, and it is unclear which patients can benefit from a follow-up study if the initial transthoracic echocardiogram (TTE) shows no signs of IE. The strict negative criteria (good ultrasound quality and no high-risk features such as significant valvular regurgitations or stenosis, pericardial effusion or intracardiac devices) have been recently proposed to avoid unnecessary follow-up echocardiograms.

Purpose

The objective of this study is to review the contemporary, real-world use of echocardiography in patients with suspected IE and analyze the potential applicability of the strict negative criteria.

Methods

We retrieved all the echocardiograms that were performed in our center for suspected or confirmed IE between January 2014 and December 2018. We defined different groups according to the strict negative criteria and reviewed the electronic clinical history to check if a definitive diagnosis of IE was established or not.

Results

We included a total of 905 TTEs. 451 (49.8%) of them fulfilled the strict negativity criteria (Group 1). In this group, IE was seldom diagnosed (n=4, 0.9%). In 338 (37.4%) patients no signs of IE were evident but they didn't fulfill the strict negative criteria (Group 2). A follow-up echocardiogram and definitive diagnosis of IE were more frequent (n=48, 14.2% and n=20, 5.9%). Finally, in 116 (12.8%) patients the initial TEE showed typical or suggestive signs of IE, in whom the diagnosis was confirmed in 48 (41.4%). The independent predictors of follow-up echocardiography were the previous history of valvular heart disease (HR 2.38 [1.39–3.89], p=0.001) or cancer (HR 0.47 [0.27–0.84], p=0.01), positive blood cultures for Enterococcus (HR 5.01 [2.34–10.73], p&lt;0.001), methicillin-sensitive Staphylococcus aureus (HR 2.8 [1.27–6.17], p=0.011) or Streptococcus (HR 2.36 [1.12–5], p=0.024), and the presence of typical or suggestive signs of infective endocarditis on initial TTE (HR 13.77 [8.6–22.05], p&lt;0.001). A definitive diagnosis of IE was confirmed in a minority of the study population (n=72, 8%). Only one readmission for underdiagnosis of IE during index hospitalization was noted on Group 2.

Conclusions

In a real-life, observational setting only a minority of patients in whom IE was suspected had a definite diagnosis. An initial TTE for suspected IE fulfilling the strict negative criteria predicts both a low probability of requesting a follow-up study and of a definitive diagnosis of IE. Further research should be performed to rationalize echocardiogram requests for suspected IE.

Funding Acknowledgement

Type of funding sources: None.

Prognostic value of vasodilator stress CMR in elderly patients with known or suspected chronic coronary syndrome

Background

In recent guidelines, non-invasive imaging techniques play a pivotal role in the management of chronic coronary syndrome (CCS). The elderly represent a large percentage of our routine CCS population and risk stratification in this scenario is challenging. The potential of vasodilator stress cardiovascular magnetic resonance (vs-CMR) for this purpose is unknown.

Purpose

We explored the prognostic value of the ischemic burden, as derived from vs-CMR, in elderly patients with known or suspected CCS.

Methods

From the general cohort of 6389 patients with known or suspected CCS submitted to undergo vs-CMR in our health department from 2001 to 2016, we performed a subanalysis of the 1225 patients &gt;70 year-old (mean age 77±5 years, 51% male). Clinical and vs-CMR characteristics were prospectively recorded. The ischemic burden (at stress first-pass perfusion imaging) was computed (using the 17-segment model). The occurrence of major adverse cardiac events (MACE) defined as all-cause death and/or non-fatal myocardial infarction (whichever occurred first) was retrospectively revised using the electronic regional health system registry.

Results

During a median follow-up of 2.7 years, 203 MACEs were registered (17%). Age (77±4 vs. 76±5 years) was not significantly different in patients with and without MACE. Larger left ventricular (LV) end-diastolic and end-systolic volume indexes, more depressed LV ejection fraction, more extensive areas with late gadolinium enhancement and ischemic burden were detected in patients with MACE (p&lt;0.001 for all comparisons). In non-revascularized patients (n=1118), the MACE rate ranged from 13% (in patients with 0–1 ischemic segments) to 35% (in those with &gt;8 ischemic segments, p&lt;0.001 for the trend). In the small subset of revascularized patients (n=107), revascularization exerted a non-significant protective effect only in patients with extensive ischemic burden (&gt;5 segments).

Conclusions

Vasodilator stress CMR represents a valuable tool to stratify risk in elderly patients with known or suspected CCS and might be helpful to guide decision-making.

Figure 1

Funding Acknowledgement

Type of funding source: None

Echocardiographic strict negative criteria for suspected infective endocarditis. Can we avoid unnecessary echocardiograms?

Background

Infective endocarditis (IE) is an uncommon but potentially lethal disease that require a timely diagnosis. Transthoracic echocardiography (TTE) has a pivotal role in diagnosis and follow-up and should be requested if there is a clinical suspicion of IE. However, it is unclear which patients can benefit from a follow-up echocardiogram if the initial TTE shows no signs of IE. The strict negative criteria (SNC) have been recently proposed to avoid unnecessary follow-up echocardiograms.

Purpose

The objective of this study is to review the contemporary, real-world use of echocardiography in patients with suspected IE and analyze the possible effect that incorporating the SNC would have in our clinical practice.

Methods

We searched the echocardiography database for the words “endoc” and “veget” to find the tests that were performed for suspected or confirmed IE between January 2014 and December 2018. We extracted and manually reviewed all the echocardiographic data and applied the SNC to patients with an initial negative TTE. We reviewed the electronic clinical history to check if a final diagnosis of IE was established or not.

Results

We included a total of 957 echocardiograms in our registry. 493 (51.5%) did not meet the SNC. The main reasons for exclusion were the occurrence of more than mild valvular regurgitation (n=293, 30.6%), the presence of typical or suggestive signs of IE (n=128, 13.3%), the evidence of more than mild valvular stenosis or sclerosis (n=105, 10.9%) and a suboptimal ultrasound quality (n=90, 9.4%). Globally, a follow-up echocardiogram was performed in 143 (14.9%) patients. Only in 25 (5.4%) of patients which fulfilled the SNC a follow-up echocardiogram was requested, compared to 60 (16%) patients which neither fulfilled the SNC nor showed echocardiographic signs of IE and 68 (53.5%) patients in which the SNC weren't met but showed echocardiographic signs of IE (p&lt;0.001). After performing a binary logistic regression model, the only independent predictor of follow-up echocardiography in patients who didn't met the SNC was the presence of typical or suggestive signs of infective endocarditis on initial TTE (HR 2.84 [2.17–3.71], p&lt;0.001).

Conclusions

1. In a real-life, observational setting an initial TTE for suspected IE that fulfilled the defined SNC predicts a low probability of requesting a follow-up echocardiography (5.4%), even though these criteria were neither reported by the echocardiographist nor probably known by the clinician in charge of the patient.

2. The number of echocardiograms avoided by applying these criteria in this context is low.

3. A follow-up echocardiogram was requested more frequently if the SNC weren't met, especially when typical or suggestive signs of IE were described in the initial TTE (53.5% vs 16%). This factor seems to be the only independent echocardiographic variable that predicts the probability of requesting a follow-up echocardiogram in this subgroup of patients.

Figure 1

Funding Acknowledgement

Type of funding source: None

Chest pain of unknown coronary origin: can exercise ECG testing contribute to long-term risk prediction on top of vasodilator stress cardiac magnetic resonance?

Background

The prognostic value of both exercise ECG testing (ExECG) and vasodilator stress cardiac magnetic resonance (VS-CMR) is well-known in patients with chest pain of unknown coronary origin. However, it is unknown whether performing both techniques can improve the risk stratification of these patients.

Purpose

We aim to confirm the additive prognostic value of ExECG and VS-CMR in a real-world cohort of patients with chest pain of unknown coronary origin.

Methods

We retrospectively included 288 patients in which ExECG and VS-CMR had been subsequently performed within one year. Clinical, ExECG and VS-CMR variables were registered. We performed univariate and multivariate analysis to check for the association of variables with the risk of MACE, defined as a combined endpoint of acute coronary syndrome (ACS), admission for heart failure (aHF) or all-cause death.

Results

During a mean follow-up of 4.2±2.15 years, we registered 27 MACE (15 ACS, 8 aHF and 8 all-cause deaths). The history of hypertension, previous coronary artery disease and/or coronary artery bypass grafting, lower maximal heart rate during ExECG (maxHR) and more extensive ischemic burden (segments with perfusion defects -PD- on stress first-pass perfusion) and myocardial necrosis (number of segments with necrosis at late gadolinium enhancement imaging) associated with the MACE endpoint. However, the only independent predictors of MACE were maxHR during ExECG (HR 0.98 [0.96–0.99], p=0.01) and more extensive segments with PD in the VS-CMR (HR 1.2 [1.07–1.34], p=0.002). We identified the best cut-off using the Youden index derived from receiver operating characteristics (ROC) analysis to predict MACE - it was ≤130bpm for maxHR during ExECG and ≥2 segments with PD on VS-CMR. These cathegories allowed us to stratify the annualized rate of MACE, which was very low (0.97%/year) in patients with normal maxHR and no PD on VS-CMR, intermediate in patients with only abnormal maxHR (1.98%/year) or PD on VS-CMR (3.24%/year) and high in patients with both abnormal maxHR and segments with PD (6.26%/year). Adding maxHR to the multivariable model including stress-induced PD by VS-CMR significantly improved the predictive power of MACE as derived from the continuous reclassification improvement index (0.47 [0.10–0.81], p&lt;0.05).

Conclusions

ExECG and VS-CMR can have an additive prognostic value to predict the long-term risk of MACE in patients with chest pain of unknown coronary origin. Patients with maxHR during ExECG ≤130bpm and ≥2 segments with PD on VS-CMR are at the highest risk of MACE.

Figure 1. MACE risk stratification.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was funded by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” (PIE15/00013, PI17/01836, and CIBERCV16/11/00486 grants) and by Generalitat Valenciana (GV/2018/116).