Exercise-induced cardiac troponin in the era of high sensitivity assays: What makes our heart sweat?

Does Myocardial Injury Occur After an Acute Aerobic Exercise Session in Patients with Refractory Angina?

BACKGROUND

It is unclear whether exercise is safe in patients with more advanced forms of coronary artery disease, such as those with refractory angina (RA).

OBJECTIVE

We aimed to determine the effect of an acute aerobic exercise session (AAES) on high-sensitivity cardiac troponin T (hs-cTnT) levels in patients with RA.

METHODS

This was a longitudinal, non-randomized, and non-controlled clinical study. Participants were recruited from April 2015 to January 2019. On a visual pain scale from 0 to 10, pain rated up to 3 was considered as the top level allowed to continue exercising. We assessed hs-cTnT at baseline and 3 hours after the AAES. The protocol consisted of 5 minutes of warm-up, 30 minutes of continuous aerobic exercise at heart rate corresponding to the anaerobic threshold or angina threshold obtained in the cardiopulmonary exercise testing, and 5 minutes of cooling down. P values less than 0.05 were considered statistically significant.

RESULTS

Thirty-two patients with RA were included (61 ± 9 years, 59.4% male). The baseline hs-cTnT concentration was 10.9 ng/L (95% confidence interval: 9.1 to 13.0 ng/L). The hs-cTnT collected 3 hours after the AAES was 11.1 ng/L (95% confidence interval: 9.1 to 13.5 ng/L). No difference occurred in hs-cTnT before and after AAES (p = 0.657).

CONCLUSIONS

A single AAES performed at the angina threshold with corresponding visual pain scale did not alter hs-cTnT in patients with RA, suggesting that no significant myocardial injury was elicited by exercising and that this exercise protocol can be considered safe.

A review of cardiac troponin I detection by surface enhanced Raman spectroscopy: Under the spotlight of point-of-care testing

Cardiac troponin I (cTnI) is a biomarker widely related to acute myocardial infarction (AMI), one of the leading causes of death around the world. Point-of-care testing (POCT) of cTnI not only demands a short turnaround time for its detection but the highest accuracy levels to set expeditious and adequate clinical decisions. The analytical technique Surface-enhanced Raman spectroscopy (SERS) possesses several properties that tailor to the POCT format, such as its flexibility to couple with rapid assay platforms like microfluidics and paper-based immunoassays. Here, we analyze the strategies used for the detection of cTnI by SERS considering POCT requirements. From the detection ranges reported in the reviewed literature, we suggest the diseases other than AMI that could be diagnosed with this technique. For this, a section with information about cardiac and non-cardiac diseases with cTnI release, including their release kinetics or cut-off values are presented. Likewise, POCT features, the use of SERS as a POCT technique, and the biochemistry of cTnI are discussed. The information provided in this review allowed the identification of strengths and lacks of the available SERS-based point-of-care tests for cTnI and the disclosing of requirements for future assays design.

Immediate and 24-h post-marathon cardiac troponin T is associated with relative exercise intensity

PURPOSE

We aimed at exploring whether cardiopulmonary fitness, echocardiographic measures and relative exercise intensity were associated with high-sensitivity cardiac troponin T (hs-TNT) rise and normalization following a marathon.

METHODS

Nighty-eight participants (83 men, 15 women; 38.72 ± 3.63 years) were subjected to echocardiographic assessment and a cardiopulmonary exercise test (CPET) before the race. hs-TNT was measured before, immediately after and at 24, 48, 96, 144 and 192 h post-race. Speed and mean heart rate (HR) during the race were relativized to CPET values: peak speed (%V_VMAX), peak HR (HR_%MAX), speed and HR at the second ventilatory threshold (HR_%VT2 and %V_VT2).

RESULTS

Hs-TNT increased from pre- to post-race (5.74 ± 5.29 vs. 50.4 ± 57.04 ng/L; p < 0.001), seeing values above the Upper Reference Limit (URL) in 95% of the participants. At 24 h post-race, 39% of the runners still exceeded the URL (High hs-TNT group). hs-TNT rise was correlated with marathon speed %V_VT2 (r = 0.22; p = 0.042), mean HR_%VT2 (r = 0.30; p = 0.007), and mean HR_%MAX (r = 0.32; p = 0.004). Moreover, the High hs-TNT group performed the marathon at a higher Speed %V_VT2 (88.21 ± 6.53 vs. 83.49 ± 6.54%; p = 0.002) and Speed %V_VMAX (72 ± 4.25 vs. 69.40 ± 5.53%; p = 0.009). hs-TNT showed no significant associations with cardiopulmonary fitness and echocardiographic measures, except for a slight correlation with left ventricular end systolic diameter (r = 0.26; p = 0.018).

CONCLUSION

Post-race hs-TNT was above the URL in barely all runners. Magnitude of hs-TNT rise was correlated with exercise mean HR; whereas, its normalization kept relationship with marathon relative speed.

Familial history of heart disease and increased risk for elevated troponin in apparently healthy individuals

BACKGROUND

Family history of heart disease (FH-HD) is associated with an increase drisk of subsequent HD. High sensitive cardiac troponin T (hs-cTnT) is arecognized biomarker of myocyte injury even in HD free patients. We examined the association between FH-HD and hs-cTnT in apparently healthy individuals.

HYPOTHESIS

FH-HD is associated with elevated hs-cTnT in apparently healthy individuals.

METHODS

In a cross sectional study we analyzed data of apparently healthy individuals (n=3,821) recruited for the Tel-Aviv Medical Center Inflammation Survey (TAMCIS). Blood samples were obtained for hs-cTnT and high sensitive CRP (hs-CRP) among other tests. FH-HD was defined as first degree family member with HD diagnosis and classified as premature if the diagnosis was done before the age of 55 for men or 65 for women.

RESULTS

Elevated hs-cTnT (>14 ng/L) was more common in FH-HD of any age, and in premature FH-HD (FH-P-HD) participants than in participants without FH-HD (4.4% vs 2.0%, p<0.001 and 4.3% vs 2.0%, p=0.001, respectively). Adjustmentfor potential risk factors with association to elevated hs-cTnT (age, sex, BMI, hypertension, diabetes, hs-CRP, smoking and physical activity), showed that FH-HD and FH-P-HD remained significantly associated with elevated hs-cTnT (OR=1.62, p=0.025 and OR=1.70, p=0.039, respectively). Furthermore, we found that a significant interaction between FH-HD or FH-P-HD and high levels ofhs-CRP (>3 mg/L) increased the risk for elevated hs-cTnT (OR=3.07, p=0.036 for FH-HD and OR=3.25, p=0.053 for FH-P-HD).

CONCLUSIONS

FH-HD and its interaction with elevated hs-CRP levels were significantly associated with elevated hs-cTnT in apparently healthy individuals suggesting that an inflammatory process may be involved in this association.