Dr. Sundeep Mishra, a noted professor of Cardiology, sheds light on of 3 major studies- SCOT HEART Trial , TRICS-3 Trial, and the effects of sleeplessness on heart health, all of which were presented at the recent European Society of Cardiology International Congress held in Munich, 2018.

 

In part of the ESC Congress 2018 updates, Dr. Mishra discusses the 3 studies in detail and provides key takeaways for each.

The “Braveheart” of Imaging- SCOT HEART Trial

CT angiography should now become a standard investigational modality to be offered to all stable CAD patients to not only clarify the diagnosis but better guide the further management.

Coronary CT Angiography Reduces 5-Year Risk of Myocardial Infarction

Chest pain is among the most common symptoms responsible for OPD and casualty visits and even hospital admissions. Conventionally, prior to performing a definitive diagnostic test like coronary angiogram (CAG) one of the physiological stress tests like TMT, SPECT, stress echocardiography etc. are performed in patients with stable coronary artery disease (CAD).

Over the past 5 decades or so these techniques have been found useful not only in aiding the diagnosis of CAD but also providing important prognostic information. Thus, they feature in the current international guidelines for the assessment of patients with stable CAD.

In recent times, however, another anatomic modality has appeared on the horizon, multi-slice CT coronary angiography (CTA) has become available which is non-invasive and has accuracy close to CAG.

Moreover, it is known to provide definitive anatomic diagnosis and thus overcome several limitations of traditional functional approaches. Meanwhile, other non-invasive physiologic imaging modalities have also become available; cardiac magnetic resonance (CMR), positron emission tomography (PET), CT myocardial perfusion imaging and real time myocardial contrast echocardiography.

This entire technological advance in the field has mandated a relook into the indications for individual modalities and draw up a new diagnostic algorithm for screening and definitive diagnosis. Last year, PROMISE trial revealed that coronary CTA, resulted in a non-significant reduction in the rate of MI as well as mortality and could be certainly an alternative to stress testing among low- to intermediate-risk patients presenting with chest pain.

A recent meta-analysis published in NEJM this year revealed that in patients with suspected stable CAD, although an initial diagnostic strategy of stress echocardiography or single photon emission CT myocardial perfusion imaging resulted in 76% and 43% fewer downstream tests respectively vs. CTA (95% CI 0.08 to 0.74; 37 to 0.87 respectively), however, it was TMT which yielded the highest downstream testing rate.

Furthermore, the estimates for death and MI were imprecise without clear discrimination between strategies. However, in all these studies the analysis were generally up to a period of 2 years.

SCOT-HEART Trial

The Scottish Computed Tomography of the HEART Trial presented in ESC in Munich 2018, was a multicenter (based in Scotland), open-label, parallel-group RCT enrolling >4000 patients with stable chest pain who had been referred to a cardiology clinic for evaluation by CTA or standard care alone.

The primary end-point was death from coronary heart disease or nonfatal MI at 5 years. The mean age was 57 years, the majority (56%) were male, over half (53%) were current smokers or ex-smokers. Nearly 5 out of 6 had a normal baseline ECG and nearly 2/3rd of all undergoing stress echocardiography had a normal result (another 1/6th were inconclusive).

The reason for these interesting findings could be that in CTA group once some atherosclerotic disease was identified the patients could have undergone an aggressive secondary prevention strategy which could have ultimately led to lowering of coronary events and even need for revascularization.

Indeed, there was some data from this trial indicating that patients who had CTA alongside standard care were more likely to be initiated on a statin and other preventive therapy than those who had standard care alone, suggesting that greater awareness of a patient's condition led to better care.

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TRICS 3- Less is more, that is the Trick

TRICS 3 study proves that patients undergoing cardiac surgery may need a BT only if blood hemoglobin levels fall below 7.5 g/dL.

Most guidelines recommend that in patients undergoing cardiac surgery there seems to be no advantage to transfuse patients whose hemoglobin level is ≥10 g/dL. However, it is not clear at what level of hemoglobin (Hb) the transfusion helps? Un-necessary blood transfusion (BTs) may cause infections, immunologic effects and even volume overload but on the other hand, acute anemia can lead to persistent, harmful tissue hypoxia.

TRICS-3 Trial: Restrictive Transfusion Appears Safe in CV Surgery

It was a large RCT conducted in 19 countries at 74 sites (on all continents except Antarctica) enrolling nearly 5000 adults undergoing cardiac surgery, randomized to restrictive use of transfusion (transfusion if Hb <7.5 g/dL) vs. liberal use of transfusion (transfusion if Hb <9.5 g/dL when in ICU or Hb <8.5 g/dL when in non- ICU ward). Patients included were higher risk (EuroSCORE ≥6) with a mean age 72 years, ~ 2/3rd male, undergoing various types of cardiac surgery; CABG only (26%), CABG and valve surgery (19%), CABG and non-valve surgery (8%), valve surgery only (29%), and other non-CABG surgery (18%).

At 6 months, the primary composite outcome occurred in 17.4% of patients in the restrictive BT group vs. 17.1% of patients in the liberal BT group (P = .006 for non-inferiority). Likewise, mortality was similar in both groups: 6.2% and 6.4% in the restrictive and liberal BT groups, respectively. There were no significant between-group differences in the secondary outcomes as well (individual components of the primary outcomes, emergency department visits, hospital readmission, or coronary revascularization).

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Insomnia Games- The business of ZZZ

Although it is an observational study it should serve as a wake-up call to take cognizance of ill effects of sleeplessness on heart health.

Sleeping five hours or less a night associated with doubled risk of cardiovascular disease

Globally, nearly 1/3 people suffer from a chronic lack of sleep one time or the other. The causes can be multiple; stress, computers, taking work home, jet lag, night shifts, but it could be sleep apnoea syndrome also. The cost sleep-less nights could be more than just bad moods and a lack of focus, it could predispose to serious medical conditions; obesity, diabetes and even heart diseases – and it could even shorten life expectancy. Sleep duration, timing, and structure vary between individuals; most need around 8 hours of good-quality sleep but anything < 7 hours is certainly less sleep.

A retrospective study of more than one million people aged 30-102 revealed a mode of eight hours sleep in normal individuals (52% slept less than 7.5 hours and 4% less than 6.5 hours per night). Recently a study evaluating more than 1 lakh healthy US Nurses for 24 years found that overall 9% of nurses working on night-shifts developed or died from heart disease while those working at least 3 night shifts/month were up to 27% more likely to develop heart disease than those who did not.

In a study presented at the ESC in Munich 2018, Bengtsson and co-workers presented findings on a study enrolling men born in 1943 and living in Gothenburg, Sweden. Participants underwent a physical examination and completed a questionnaire on current health conditions, average sleep duration, physical activity, and smoking.

The men were divided into four groups according to their self-estimated average sleep duration at the start of the study: ≤5 hours, 6 hours, 7-8 hours (considered normal sleep duration), and >8 hours. Participants were followed-up for 21 years for the occurrence of major cardiovascular events, which included heart attack, stroke, hospitalization due to heart failure, coronary revascularisation, or death from cardiovascular disease. There were 759 men who had complete data.

The magnitude of increased cardiovascular risk associated with insufficient sleep is similar to that of smoking or having diabetes at age 50 and thus lack of sleep could also be considered a risk factor for CAD as well.

To read Part 1 of the ESC Congress 2018 Updates by Dr. Sundeep Mishra, click Top 3 promising cardiac therapies presented at ESC Congress 2018: Dr. Mishra

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