Effectiveness of percutaneous coronary intervention in patients with silent myocardial ischemia (post hoc analysis of the COURAGE trial)

Silent Myocardial Ischemia: From Pathophysiology to Diagnosis and Treatment

Silent myocardial ischemia (SMI), characterized by a lack of overt symptoms despite an inadequate blood supply to the myocardium, remains a challenging entity in cardiovascular medicine. The pathogenesis involves intricate interactions of vascular, neurohormonal, and metabolic factors, contributing to perfusion deficits without the characteristic chest pain. Understanding these mechanisms is pivotal for recognizing diverse clinical presentations and designing targeted interventions. Diagnostic strategies for SMI have evolved from traditional electrocardiography to advanced imaging modalities, including stress echocardiography, single-photon emission computed tomography (SPECT), positron emission tomography (PET), and cardiac magnetic resonance imaging (MRI). Treating SMI is a matter of ongoing debate, as the available evidence on the role of invasive versus medical management is controversial. This comprehensive review synthesizes current knowledge of silent myocardial ischemia, addressing its pathophysiology, diagnostic modalities, and therapeutic interventions.

Utility of screening for silent myocardial ischaemia in diabetes with an annual electrocardiogram

BACKGROUND AND METHODS

Asymptomatic coronary artery disease (CAD) is common in people with diabetes mellitus, but there is a lack of consensus regarding appropriate screening for the condition. We performed a 12-lead electrocardiogram (ECG) on 312 consecutive participants with diabetes mellitus attending for routine annual outpatient review in order to determine the effectiveness of a yearly ECG in screening people with diabetes for asymptomatic CAD.

RESULTS

Three of 312 participants (0.96%, 95% CI 0.2%-2.78%) had a newly identified ECG abnormality. One person had newly discovered atrial fibrillation. Two people had abnormalities which prompted further investigation for asymptomatic CAD. One of these participants underwent percutaneous coronary intervention. Seventeen further participants had abnormalities on ECG which had been previously documented, the majority having been present since their diagnosis of diabetes.

CONCLUSION

A low positive yield of routine annual ECG in our study does not support its use as a screening tool for asymptomatic CAD in diabetes. Our findings support advice to perform an ECG at diagnosis of diabetes and to repeat only if a person develops relevant symptoms.

Long-term mortality in asymptomatic patients with stable ischemic heart disease undergoing percutaneous coronary intervention

OBJECTIVES

Patients with stable ischemic heart disease (SIHD) may present with a variety of symptoms including typical angina, angina equivalents such as dyspnea or no symptoms. We sought to determine whether symptom status affects periprocedural safety and long-term mortality in patients undergoing PCI.

METHODS

Prospectively enrolled consecutive patients undergoing PCI for SIHD at six hospitals in Australia between 2005 to 2018 as part of the Melbourne Interventional Group registry. Symptom status was recorded at the time of PCI and patients undergoing staged PCI were excluded.

RESULTS

Overall, 11,730 patients with SIHD were followed up for a median period of 5 years (maximum 14.0 years, interquartile range 2.2-9.0 years) with 1,317 (11.2%) being asymptomatic. Asymptomatic patients were older, and more likely to be male, have triple-vessel disease, with multiple comorbidities including renal failure, diabetes and heart failure (all P < .01). These patients had significantly higher rates of periprocedural complications and major adverse cardiovascular events at 30-days. Long-term mortality was significantly higher in asymptomatic patients (27.2% vs 18.0%, P < .001). On cox regression for long-term mortality, after adjustment for more important clinical variables, asymptomatic status was an independent predictor (Hazard ratio (HR) 1.39 95% CI 1.16-1.66, P < .001).

CONCLUSIONS

In a real-world cohort of patients undergoing revascularization for SIHD, absence of symptoms was associated with higher rates of periprocedural complications and, after adjustment for more important clinical variables, was an independent predictor of long-term mortality. As the primary goal of revascularization in SIHD remains angina relief, the appropriateness of PCI in the absence of symptoms warrants justification.

Angiographic Complete versus Clinical Selective Incomplete Percutaneous Revascularization in Heart Failure Patients with Multivessel Coronary Disease

Background

Patients with multivessel disease (MVD) often pursue complete revascularization (CR) during percutaneous coronary intervention (PCI) to improve prognosis. However, angiographic CR is not always feasible and is associated with some procedure-related complications in heart failure (HF) patients with MVD. Clinical selective incomplete revascularization (IR) may be reasonable for these high-risk patients, but its role in long-term outcomes remains uncertain.

Methods

Six hundred patients with HF and MVD submitted to PCI were enrolled. Major adverse cardiac events (MACEs) were defined as a composite of recurrent myocardial infarction, any revascularization, and all-cause mortality at 5 years.

Results

During a mean follow-up period of 3.7 ± 1.9 years, there was no significant difference in 5-year MACEs between selective IR and successful angiographic CR in HF patients with MVD. However, patients who failed CR had a significantly greater incidence of 5-year MACEs than those in the other two groups (failed CR: 46.4% vs. selective IR: 27.7% vs. successful CR: 27.8%, p < 0.001).

Conclusions

Long-term outcomes of selective IR were comparable with those of successful angiographic CR in HF patients with MVD. However, patients that failed CR showed 2.53-fold increased risk of MACEs compared to patients undergoing either selective IR or successful angiographic CR. A more comprehensive planning strategy should be devised before PCI in HF patients with MVD.

The year in review: advances in interventional cardiology in 2019

PURPOSE OF REVIEW

Major studies in interventional cardiology in 2019 have added substantial new evidence for pharmaco-invasive management of coronary artery disease. The review highlights the main findings of a selection of these trials and summarizes their impact on clinical practice.

RECENT FINDINGS

Recent randomized studies examining the efficacy of revascularization or medical treatment in stable ischemic heart disease (SIHD), treatment of acute coronary syndromes, emerging interventional devices, adjunctive pharmacotherapy, and intravascular imaging and physiology guidance have substantially advanced the evidenced-based knowledge in interventional cardiology.

SUMMARY

Patients with SIHD and at least moderate myocardial ischemia have similar event-free survival after an initial conservative strategy of optimal medical therapy versus an upfront invasive strategy. Quality of life and angina-free status are significantly improved with revascularization. Percutaneous coronary intervention (PCI) and coronary artery bypass grafting provide similar 5-year outcomes in patients with left main coronary artery disease and low or intermediate disease complexity. An initially conservative management is equally effective as an early invasive approach in patients with out-of-hospital cardiac arrest without ongoing ischemia. Patients with ST-segment elevation myocardial infarction and multivessel disease benefit from staged complete revascularization after primary PCI. Post-PCI, patients with atrial fibrillation requiring anticoagulation can safely and effectively be treated with P2Y12 inhibitor monotherapy without aspirin. Lastly, intravascular imaging guidance improves post-PCI outcomes, warranting increased use in clinical practice.

Higher coronary artery calcification score is associated with adverse prognosis in patients with stable angina pectoris

BACKGROUND

Coronary artery calcification (CAC) indicates the presence of atherosclerotic lesions and serves as a marker of prognosis in patients with coronary artery disease (CAD). This study evaluated the value of the CAC score for determining the prognosis of patients with stable angina pectoris (SAP).

METHODS

A total of 106 consecutive patients with SAP were enrolled in this study from January 2011 to June 2014; from these patients, 640 multi-slice computer tomography (MSCT) samples were used to obtain CAC scores. The CAC scores were calculated according to the standard Agatston calcium scoring algorithm. All subjects were divided into a lower CAC score group (CAC score, ≤300) and a higher CAC score group (CAC score, >300). Major adverse cardiac events (MACE) were followed-up, and the non-event survival time was recorded. The relationships between the CAC score and both clinical characteristics and MACE were then analysed.

RESULTS

The CAC positively correlated with age and the creatinine (Cr) level. Compared with patients who received lower CAC scores, the rates of percutaneous coronary intervention (PCI), MACE and multi-vessel disease were significantly higher in patients who received higher CAC scores. The Cox regression analysis results showed that the CAC score [pre-standard deviation (SD)] was a risk factor for the no-event survival time [hazard ratio (HR), 3.06; 95% confidence interval (CI), 1.47-6.38; P<0.05 for all]. However, the Kaplan-Meier analysis suggested that the rates of MACE did not differ between patients who were treated with PCI plus medical therapy and those who were treated with optimal medical therapy alone in both the higher and lower CAC score groups.

CONCLUSIONS

The CAC scores (per-SD) and MACE strongly and positively correlated in patients with SAP, and PCI was not related to the clinical prognosis of patients with SAP in either group.

Impact of repeat myocardial revascularization on outcome in patients with silent ischemia after previous revascularization

OBJECTIVES

This study sought to compare the survival of asymptomatic patients with previous revascularization and ischemia, who subsequently underwent repeat revascularization or medical therapy (MT).

BACKGROUND

Coronary artery disease is progressive and recurring; thus, stress myocardial perfusion scintigraphy (MPS) is widely used to identify ischemia in patients with previous revascularization.

METHODS

Of 6,750 patients with previous revascularization undergoing MPS between January 1, 2005, and December 31, 2007, we identified 769 patients (age 67.7 ± 9.5 years; 85% men) who had ischemia and were asymptomatic. A propensity score was developed to express the associations of revascularization. Patients were followed up over a median of 5.7 years (interquartile range: 4.7 to 6.4 years) for all-cause death. A Cox proportional hazards model was used to identify the association of revascularization with all-cause death, with and without adjustment for the propensity score. The model was repeated in propensity-matched groups undergoing MT versus revascularization.

RESULTS

Among 769 patients, 115 (15%) underwent revascularization a median of 13 days (interquartile range: 6 to 31 days) after MPS. There were 142 deaths; mortality with MT and revascularization were 18.3% and 19.1% (p = 0.84). In a Cox proportional hazards model (chi-square test = 89.4) adjusting for baseline characteristics, type of previous revascularization, MPS data, and propensity scores, only age and hypercholesterolemia but not revascularization were associated with mortality. This result was confirmed in a propensity-matched group.

CONCLUSIONS

Asymptomatic patients with previous revascularization and inducible ischemia on MPS realize no survival benefit from repeat revascularization. In this group of post-revascularization patients, an ischemia-based treatment strategy did not alter mortality.