What's new in cardiovascular medicine

The following represent additions to UpToDate from the past six months that were considered by the editors and authors to be of particular interest. The most recent What's New entries are at the top of each subsection.

AORTIC DISEASE

Moderate hypothermia during aortic arch surgery with antegrade cerebral perfusion (March 2024)

Observational data have supported a shift from deep to moderate hypothermia during circulatory arrest for aortic arch surgery, particularly with adjunctive antegrade cerebral perfusion (ACP). A recent trial has now compared outcomes for 251 patients undergoing aortic arch surgery with ACP and randomly assigned to deep (≤20.0°C), low-moderate (20.1 to 24.0°C), or high-moderate (24.1 to 28.0°C) circulatory arrest temperature [1]. At one-month follow-up, the three groups had similar neurocognitive and neuroimaging outcomes and similar mortality, major morbidity, and quality of life. The volume of transfused blood products was higher in the deep group, but transfusion-related complications were not different. Based on this trial, moderate (20.1 to 28.0°C) rather than deep hypothermia is reasonable during aortic arch surgery when ACP is also used. Whether a low-moderate or high-moderate temperature is selected depends on the complexity of the arch intervention and the anticipated duration of hypothermia. (See "Overview of open surgical repair of the thoracic aorta", section on 'Hypothermic circulatory arrest'.)

ARRHYTHMIAS

Long-term effects of cardiac resynchronization therapy (March 2024)

In patients with heart failure with reduced ejection fraction (HFrEF), left bundle branch block with QRS duration ≥120 ms, and New York Heart Association class II to III symptoms, cardiac resynchronization therapy (CRT) has short-term mortality benefits, but long-term data are lacking. In a recent study that reported long-term follow-up (median 7.7 years) of over 1000 patients randomly assigned to CRT plus an implantable cardioverter-defibrillator (ICD) or ICD only, 15-year mortality rates were 71 and 76 percent, respectively [2]. Notably, the analysis was restricted to centers who enrolled a high volume of patients in the original trial. In patients with indications for CRT, mortality is high, and we recommend CRT therapy to reduce the short- and long-term risk of mortality. (See "Cardiac resynchronization therapy in systolic heart failure: Indications and choice of system", section on 'HF symptoms, LBBB with QRS ≥150 ms, EF ≤35 percent'.)

Cardiac pacemaker or defibrillator upgrade to provide cardiac resynchronization (March 2024)

In patients with heart failure with reduced ejection fraction (HFrEF) who have a cardiac implantable electronic device (CIED; ie, pacemaker or internal cardioverter-defibrillator) but may benefit from cardiac resynchronization therapy (CRT), there is concern that the risk of device upgrade to a CRT-capable system may exceed the benefits of such an upgrade. In a recent trial in over 350 patients with HFrEF, a pre-existing CIED, and an indication for CRT, patients randomly assigned to undergo CIED upgrade had a lower risk of heart failure hospitalization over a median of 12.4 months compared with those who did not undergo system upgrade [3]. The rate of mortality was similar between the two groups. In patients with a pre-existing CIED who meet criteria for CRT, we recommend upgrade of the existing system. (See "Cardiac resynchronization therapy in systolic heart failure: Indications and choice of system", section on 'Identify contraindications'.)

Pulsed field ablation for atrial fibrillation (February 2024)

Pulsed field ablation, which delivers microsecond high-voltage electric pulses to cause localized cell death, may enable more precisely targeted ablation for atrial fibrillation (AF). In a single-blind trial in over 600 patients with refractory paroxysmal AF who were randomly assigned to undergo pulsed field ablation or thermal ablation (with either radiofrequency or cryoballoon ablation), treatment success rates were similar between the groups [4]. Rates of serious adverse events were also similar in the two groups. In December 2023 [5]and January 2024 [6], the US Food and Drug Administration approved pulsed field ablation systems to treat paroxysmal AF. (See "Atrial fibrillation: Catheter ablation", section on 'Comparison of pulsed field and thermal ablation'.)

Pericarditis after catheter ablation for atrial fibrillation (January 2024)

Acute pericarditis is one of the complications of catheter ablation for atrial fibrillation (AF), but its incidence and risk factors have not been well defined. In a series of over 1500 patients who underwent catheter ablation for AF, acute pericarditis was diagnosed in nearly 4 percent with median onset at one day post procedure [7]. The risk of acute pericarditis was higher with radiofrequency ablation than with cryoablation; cardiac tamponade occurred in less than 10 percent of patients with pericarditis. These data help inform risk assessment for patients with AF. (See "Atrial fibrillation: Catheter ablation", section on 'Pericarditis'.)

Anticoagulation for device-detected atrial fibrillation (January 2024)

Device-detected (subclinical) atrial fibrillation (AF) is common in patients with an implanted cardiac rhythm device and associated with an increased risk of ischemic stroke; however, the risks and benefits of anticoagulation in this setting are uncertain. In a meta-analysis of two randomized controlled trials comparing direct oral anticoagulants (edoxaban or apixaban) with placebo or aspirin in patients with device-detected AF, oral anticoagulation reduced the risk of ischemic stroke but increased the risk of major bleeding [8]. These findings will help inform the management of patients with device-detected AF. (See "Atrial fibrillation in adults: Selection of candidates for anticoagulation", section on 'Paroxysmal AF'.)

CORONARY HEART DISEASE, ACUTE

Physiologic assessment of coronary artery disease severity (May 2024)

During acute myocardial infarction (MI), the severity of nonculprit coronary artery disease is typically assessed with invasive coronary angiography, but assessment with intracoronary pressure measurements may improve the selection of coronary lesions for revascularization. In a recently published trial in over 1500 patients with acute MI, patients randomly assigned to percutaneous coronary intervention (PCI) of all nonculprit lesions (ie, complete revascularization) guided by fractional flow reserve (FFR) measurement or to culprit-only PCI had similar rates of death and MI after a median of nearly five years [9]. The trial was stopped early after evidence from other trials suggested a lower rate of death and MI with complete revascularization. In patients with acute MI and nonculprit coronary artery stenosis, angiographic assessment is sufficiently accurate to identify target lesions for revascularization; FFR assessment is not routinely required. (See "Acute coronary syndromes: Approach to nonculprit lesions", section on 'Assessment of nonculprit lesion anatomy'.)

Choice of anticoagulant for percutaneous coronary intervention in non-ST-elevation myocardial infarction (March 2024)

In patients with non-ST-elevation myocardial infarction (NSTEMI) who will undergo percutaneous coronary intervention (PCI), the optimal agent for intraprocedural anticoagulation remains uncertain. In a recent meta-analysis that included over 12,000 patients with NSTEMI who underwent PCI, heparin and bivalirudin had similar rates of 30-day mortality, recurrent myocardial infarction, and stent thrombosis [10]. The rate of major bleeding events was lower with bivalirudin, but the clinical significance of this finding is unclear; most patients in the analysis underwent femoral arterial access, while most patients in modern practice undergo radial arterial access, which reduces the risk of bleeding regardless of the anticoagulant used for PCI. In patients with NSTEMI who will undergo PCI, we suggest intraprocedural anticoagulation with either unfractionated heparin or bivalirudin. (See "Anticoagulant therapy in non-ST-elevation acute coronary syndromes", section on 'Invasive approach'.)

Liberal transfusion strategy for acute myocardial infarction (December 2023)

Restrictive transfusion (transfusing at a lower hemoglobin, typically <7 or 8 g/dL) is appropriate for most patients based on evidence from randomized trials, but trial data for patients with acute myocardial infarction (MI) have been slower to accumulate. In the MINT trial, which randomly assigned 3504 patients with acute MI and anemia to a restrictive or liberal (transfusing for hemoglobin <10 g/dL) strategy, there was a trend toward better outcomes with the liberal strategy without an increased risk of adverse events [11]. We now suggest a liberal strategy for acute MI. A slightly lower hemoglobin may be reasonable for stable, asymptomatic patients, and patients with hemodynamic instability may require a higher hemoglobin. (See "Indications and hemoglobin thresholds for RBC transfusion in adults", section on 'Acute MI'.)

HEART FAILURE

Gene silencer therapy for the treatment of cardiac amyloidosis (May 2024)

In patients with transthyretin (ATTR) cardiac amyloidosis, infiltration of the myocardium by ATTR leads to heart failure (HF); whether drugs that inhibit transthyretin production (eg, patisiran, an RNA interference agent) effectively treat this condition is unknown. In a recent trial in over 350 patients with ATTR cardiac amyloidosis, patients randomly assigned to treatment with patisiran or placebo had similar rates of death, hospitalization, or urgent visits for HF over 12 months [12]. While walk distance and quality of life improved with patisiran, the lack of an effect on clinically important endpoints and availability of more effective therapies limit its role in ATTR cardiac amyloidosis. In patients with ATTR cardiac amyloidosis and HF, we recommend treatment with tafamidis; the role of gene silencing agents remains unclear. (See "Cardiac amyloidosis: Treatment and prognosis", section on 'Disease-specific therapy for ATTR amyloidosis'.)

Acoramidis for the treatment of transthyretin cardiac amyloidosis (May 2024)

In patients with transthyretin (ATTR) cardiac amyloidosis and heart failure (HF) symptoms, treatment with an agent that prevents cleavage of ATTR tetramers has been shown to improve survival. In a recent trial in over 600 patients with ATTR cardiac amyloidosis and HF symptoms, patients randomly assigned to treatment with the ATTR stabilizer acoramidis had a lower rate of hospitalization over 30 months compared with placebo [13]. In contrast with tafamidis, a drug with a similar mechanism of action, acoramidis did not reduce mortality compared with placebo. For patients with ATTR cardiac amyloidosis and HF symptoms, we recommend treatment with tafamidis. (See "Cardiac amyloidosis: Treatment and prognosis", section on 'Disease-specific therapy for ATTR amyloidosis'.)

Intravenous iron in heart failure (April 2024)

Individuals with heart failure (HF) and iron deficiency should be treated, but expert groups differ on the perceived benefits. In a new meta-analysis that included over 4500 patients participating in randomized trials, intravenous iron reduced the rate of cardiovascular hospitalizations compared with placebo; all-cause mortality was not reduced [14]. This supports our suggested approach of using intravenous iron, although oral iron may be reasonable. Iron supplementation should be stopped once stores are repleted, as excess iron deposition is cardiotoxic. (See "Evaluation and management of anemia and iron deficiency in adults with heart failure", section on 'Iron supplementation'.)

Cardiac pacemaker or defibrillator upgrade to provide cardiac resynchronization (March 2024)

In patients with heart failure with reduced ejection fraction (HFrEF) who have a cardiac implantable electronic device (CIED; ie, pacemaker or internal cardioverter-defibrillator) but may benefit from cardiac resynchronization therapy (CRT), there is concern that the risk of device upgrade to a CRT-capable system may exceed the benefits of such an upgrade. In a recent trial in over 350 patients with HFrEF, a pre-existing CIED, and an indication for CRT, patients randomly assigned to undergo CIED upgrade had a lower risk of heart failure hospitalization over a median of 12.4 months compared with those who did not undergo system upgrade [3]. The rate of mortality was similar between the two groups. In patients with a pre-existing CIED who meet criteria for CRT, we recommend upgrade of the existing system. (See "Cardiac resynchronization therapy in systolic heart failure: Indications and choice of system", section on 'Identify contraindications'.)

Palliative telehealth for patients with COPD, HF, and ILD (February 2024)

Although adults with advanced chronic obstructive pulmonary disease (COPD), heart failure (HF), and interstitial lung disease (ILD) have poor quality of life, data on the efficacy of palliative care measures are limited. In a trial of 306 patients who were at high risk of death due to advanced COPD, HF, or ILD, those assigned to receive six nurse phone calls for symptom management and six social worker phone calls for psychosocial care had higher quality of life (based on standardized questionnaires) at six months compared with those who received usual care [15]. Telephonic palliative care interventions may be an important tool for patients with advanced cardiopulmonary disease. (See "Palliative care for adults with nonmalignant chronic lung disease", section on 'Use and benefits of palliative care'.)

PREVENTIVE CARDIOLOGY

The Preventing Risk of Cardiovascular Disease EVENTS (PREVENT) calculator (February 2024)

Guidelines for primary prevention of cardiovascular disease (CVD) recommend using a risk calculator to estimate atherosclerotic CVD (ASCVD) risk. However, risk calculators derived from older databases may not reflect current risk in diverse populations. To provide contemporary estimates of ASCVD risk, the PREVENT calculator was derived and validated in over 6.6 million adults to estimate 10- and 30-year risks of CVD and its subtypes, heart failure and ASCVD [16,17]. The PREVENT calculator inputs include standard CVD risk measures (eg, age, sex, body mass index, diabetes, lipid levels, smoking history, blood pressure, and kidney function); the full model also includes albuminuria, hemoglobin A1C, and zip code (which estimates social deprivation). The PREVENT calculator is a valuable tool for individualizing risk assessment and discussing the primary prevention of ASCVD with patients. (See "Atherosclerotic cardiovascular disease risk assessment for primary prevention in adults: Our approach", section on 'Choosing a risk calculator'.)

TRANSPLANTATION

Thyroid hormone administration in deceased organ donors (December 2023)

Thyroid hormone administration has been a longstanding component of some organ procurement protocols due to concern that acute hypothyroidism might contribute to hemodynamic instability and left ventricular dysfunction, reducing heart and other organ procurement; however, evidence for the practice has been inconsistent. In a recent trial of 838 hemodynamically unstable, brain-dead donors assigned to receive a levothyroxine infusion or saline placebo, there was little to no difference in number of hearts transplanted or 30-day cardiac graft survival [18]. Recovery of other organs was similarly unaffected. More cases of severe hypertension or tachycardia occurred in the levothyroxine group than in the saline group. Based on these data, we suggest avoiding thyroid hormone administration in deceased organ donors. (See "Management of the deceased organ donor", section on 'Thyroid hormone'.)

VALVULAR HEART DISEASE

Choice of intervention for aortic stenosis with low surgical risk (November 2023)

The choice of intervention for severe aortic stenosis (AS) is based upon an individualized assessment by a multidisciplinary heart valve team. Two randomized trials reported outcomes for transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) in selected low surgical risk patients with severe AS [19,20]:

●In one trial in which nearly 1500 patients were randomly assigned to TAVI with a self-expanding valve or SAVR, rates of mortality, disabling stroke, and aortic valve rehospitalization at four years were similar in the two groups.

●In another trial in which 1000 patients were randomly assigned to TAVI with a balloon-expanding valve or SAVR, rates of mortality, stroke, and rehospitalization at five years were similar in the two groups.

These trials indicate generally favorable results for TAVI up to four and five years for selected low surgical risk patients with severe AS and anatomical suitability for TAVI; additional data, including longer-term outcomes, will further inform the choice of intervention in this clinical setting. (See "Choice of intervention for severe calcific aortic stenosis", section on 'In low-risk symptomatic patients'.)