does the MDBT42Q,2v04 have i2c interface?

You need to add:

var P = {
  HRM_SCL : scl_pin,
  P.HRM_SDA : sda_pin
};
getHRM();

At the end of your code and it should work.

what do I need to in order to connect the device?

You said you had it connected to Arduino and working? Just connect it as you did there.