Coronary stent length predicts PCI-induced cardiac myonecrosis

Evaluation of microcirculatory protection in percutaneous revascularisation: A stent implantation technique and device comparison

BACKGROUND

Coronary microvascular dysfunction (CMD) after percutaneous coronary intervention (PCI) is prognostically important and may also be a cause of persistent angina. The stent balloon inflation technique or material properties may influence the degree of CMD post-PCI.

METHODS

Thirty-six patients with stable angina attending for elective PCI were randomized to either slow drug eluting stent (DES) implantation technique (DES slow group): +2 atm. every 5 s., maintained for a further 30 s or a standard stent implantation technique (DES std group): rapid inflation and deflation. PressureWire X with thermodilution at rest and hyperemia and optical coherence tomography (OCT) were performed pre- and post-PCI. Combined primary endpoints were changes in index of microvascular resistance (delta IMR) and coronary flow reserve (delta CFR) following PCI. The secondary endpoints included differences in cardiac troponin I (delta cTnI) at 6 h post-PCI, Seattle angina questionnaire (SAQ) at 1, 3, 6, and 12 months and OCT measures of stent results immediately post-PCI and at 3 months.

RESULTS

Both groups were well matched, with similar baseline characteristics and OCT-defined plaque characteristics. Delta IMR was significantly better in the DES slow PCI arm with a median difference of -4.14 (95% CI -10.49, -0.39, p = 0.04). Delta CFR was also numerically higher with a median difference of 0.47 (95% CI -0.52, 1.31, p = 0.46). This did not translate to improved delta median cTnI (1.5 (34.8) vs. 0 (27.5) ng/L, p = 0.75) or median SAQ score at 3 months, (85 (20) vs. 95 (17.5), p = 0.47).

CONCLUSION

Slow stent implantation is associated with less CMD after elective PCI in patients with stable angina.

Remote Ischemic Conditioning in Elective PCI?

This review examines the rationale for using remote ischemic conditioning (RIC) in elective percutaneous coronary intervention (PCI) to prevent procedure-related ischemia-reperfusion injury and justifies the importance of periprocedural biomarker elevation following elective PCI as a valid target for RIC. We review the evidence for the use of RIC as a treatment in this setting and document the salutary rules that must be followed to successfully translate RIC for clinical benefit.

Periprocedural myocardial infarction during percutaneous coronary intervention in an academic tertiary centre in Johannesburg

BACKGROUND

Percutaneous coronary intervention (PCI) is effective therapy for significant atherosclerotic coronary artery disease. Despite medical and technological advances in PCI, periprocedural myocardial infarction (PMI) remains a common complication. The frequency and factors associated with PMI have been well investigated in the developed world, yet there is a paucity of data from the developing world, especially Sub-Saharan Africa.

METHODS

We prospectively enrolled 153 adult patients undergoing PCI at the Charlotte Maxeke Johannesburg Academic Hospital from the 1st of February 2014 to 31st October 2014. Periprocedural Creatinine Kinase-MB and hs-Troponin I were routinely measured before PCI and at 16-24h post-procedure. The third universal definition of myocardial infarction was used to define a PMI event.

RESULTS

152 participants met the inclusion criteria and were analysed for PMI. 70.4% participants were male. The mean age was 58.8 (SD 10.9) years old. Sixteen (10.5%) participants fulfilled the criteria for PMI. Side branch pinching with preserved TIMI III flow was noted in 62.5% of PMI cases. Duration of procedure (P=0.007), right coronary artery intervention (p=0.042) and total stent length (p=0.045) were independently associated with PMI.

CONCLUSION

PMI occurred in 10.5% of cases undergoing PCI. This is consistent with the prevalence of PMI internationally. Larger multicentre studies are required in our demographic region to further define relevant predictors and outcomes associated with PMI.

Microvascular dysfunction in the immediate aftermath of chronic total coronary occlusion recanalization

OBJECTIVES

The aim of this study was to compare microvascular resistance under both baseline and hyperemic conditions immediately after percutaneous coronary intervention (PCI) of a chronic total occlusion (CTO) with an unobstructed reference vessel in the same patient

BACKGROUND

Microvascular dysfunction has been reported to be prevalent immediately after CTO PCI. However, previous studies have not made comparison with a reference vessel. Patients with a CTO may have global microvascular and/or endothelial dysfunction, making comparison with established normal values misleading.

METHODS

After successful CTO PCI in 21 consecutive patients, coronary pressure and flow velocity were measured at baseline and hyperemia in distal segments of the CTO/target vessel and an unobstructed reference vessel. Hemodynamics including hyperemic microvascular resistance (HMR), basal microvascular resistance (BMR), and instantaneous minimal microvascular resistance at baseline and hyperemia were calculated and compared between reference and target/CTO vessels.

RESULTS

After CTO PCI, BMR was reduced in the target/CTO vessel compared with the reference vessel: 3.58 mm Hg/cm/s vs 4.94 mm Hg/cm/s, difference -1.36 mm Hg/cm/s (-2.33 to -0.39, p = 0.008). We did not detect a difference in HMR: 1.82 mm Hg/cm/s vs 2.01 mm Hg/cm/s, difference -0.20 (-0.78 to 0.39, p = 0.49). Instantaneous minimal microvascular resistance correlated strongly with the length of stented segment at baseline (r = 0.63, p = 0.005) and hyperemia (r = 0.68, p = 0.002).

CONCLUSIONS

BMR is reduced in a recanalized CTO in the immediate aftermath of PCI compared to an unobstructed reference vessel; however, HMR appears to be preserved. A longer stented segment is associated with increased microvascular resistance. © 2016 Wiley Periodicals, Inc.

Effect of the composition of atherosclerotic plaques and rate of platelet aggregation on elevation of serum levels of cardiac troponin T after percutaneous coronary interventions

PURPOSE

Elevation of the levels of myocardial biomarkers after percutaneous coronary intervention (PCI) has prognostic value in patients with coronary heart disease. We explored the relationship between elevation of the serum level of cardiac troponin T (cTnT) after PCI and platelet aggregation rate and coronary plaque composition.

METHODS

Eighty patients with unstable angina pectoris underwent PCI and were divided into two groups according to serum cTnT level 24 hours after PCI: group I (cTnT ≥2 times the normal level) and group II (cTnT <2 times the normal level). Coronary plaque composition was measured with virtual histology-intravascular ultrasound. Platelet aggregation rate was detected immediately before and 24 hours after PCI.

RESULTS

Compared with the patients in group II, patients in group I showed more unstable plaques, a larger necrotic core area (20.88 ± 8.04% vs. 15.31 ± 5.48%, P < 0.05), higher platelet aggregation rate (51.47 ± 12.72% vs. 44.78 ± 13.29%, P < 0.05), and longer stents. The serum cTnT level 24 hours after PCI was positively correlated with the necrotic core area.

CONCLUSIONS

In patients with unstable angina pectoris, a large necrotic core, high rate of platelet aggregation, and stent length are predictors of cTnT elevation after PCI.

Peri-procedural myocardial injury during percutaneous coronary intervention: an important target for cardioprotection

Percutaneous coronary intervention (PCI) has become the predominant procedure for coronary revascularization in patients with both stable and unstable coronary artery disease (CAD). Over the past two decades, technical advances in PCI have resulted in a better and safer therapeutic procedure with minimal procedural complications. However, about 30% of patients undergoing elective PCI sustain myocardial injury arising from the procedure itself, the extent of which is significant enough to carry prognostic importance. The peri-procedural injury which accompanies PCI might therefore reduce some of the beneficial effects of coronary revascularization. The availability of more sensitive serum biomarkers of myocardial injury such as creatine phosphokinase MB isoenzyme (CK-MB), Troponin T, and Troponin I has enabled the quantification of previously undetectable myocardial injury. Peri-procedural myocardial injury (PMI) can also be visualized by cardiac magnetic resonance imaging, a technique which allows the detection and quantification of myocardial necrosis following PCI. The identification of CAD patients at greatest risk of sustaining PMI during PCI would allow targeted treatment with novel therapies capable of limiting the extent of PMI or reducing the number of patients experiencing PMI.